FAQs On Informatica by pcherukumalla

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									   2011
Informatica




   Pavan
   1/5/2011
                 Informatica Questions & Answers
1) How can you recognise whether or not the newly added rows in the source are
gets insert in the target?
Ans) 1.checking target success rows in the workflow monitor
2.through scd type2 flag version

2) What is the difference between Informatica 7.0 and 8.0 ?
Ans)
                   Informatica 7.0                               Informatica 8.1.1
Architectur     Informatica 7.0 is a client        PC8 is service-oriented for modularity, scalability
e               server architecture where                            and flexibility.
                  8.0 is service oriented
                        architecture
Service                                        The Repository Service and Integration Service (as
                                                  replacement for Rep Server and Informatica
                                                         Server) can be run on different
                                                computers in a network (so called nodes), even
                                                                  redundantly.
Manageme                                        Management is centralized, that means services
nt                                             can be started and stopped on nodes via a central
                                                                 web interface.
Tools                                              Client Tools access the repository via that
                                                 centralized machine, resources are distributed
                                                                  dynamically.
Portability                                          Running all services on one machine is still
                                                                  possible, of course.
Supports                                           . It has a support for unstructured data which
                                               includes spreadsheets, email, Microsoft Word files,
                                                  presentations and .PDF documents. It provides
                                                  high availability, seamless fail over, eliminating
                                                                single points of failure.
Performanc         grid and pushdown           It has added performance improvements (To bump
e              optimization is not there in      up systems performance, Informatica has added
                7.0 but in 8.0 these are            "push down optimization" which moves data
                        available               transformation processing to the native relational
                                                      database I/O engine whenever its is most
                                                                     appropriate.)
Capabilities    Through 7.0 migration is               Informatica has now added more tightly
                critical where as with 8.0      integrated data profiling, cleansing, and matching
                migration is possible and                             capabilities.
                           easy
web                                                  Informatica has added a new web based
                                                               administrative console.
Additional                                     Ability to write a Custom Transformation in C++ or
Transforma                                       Java. Midstream SQL transformation has been
tions                                                       added in 8.1.1, not in 8.1.
               encryption and description                       User defined functions




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                    Informatica Questions & Answers

                   is not in 7.0 possible with
                               8.0
                     7.0 we cant change the           .Dynamic configuration of caches and partitioning
                  lookup cache size but with
                     8.0 we can change the
                        lookup cache size
                                                  Power Center 8 release has "Append to Target file"
                                                  feature.


3) Performance tuning in Informatica?
Ans)
Network connections: The performance of the Informatica Server is related to network
connections. Data generally moves across a network at less than 1 MB per second, whereas
a local disk moves data five to twenty times faster. Thus network connections often affect
on session performance. So avoid network connections.
Flat files: If your flat files stored on a machine other than the informatica server, move
those files to the machine that consists of informatica server.
Relational data sources: Minimize the connections to sources, targets and informatica server
to improve session performance. Moving target database into server system may improve
session performance.
Staging areas: If u uses staging areas u force informatica server to perform multiple data
passes. Removing of staging areas may improve session performance.
Distributing load: Distributing the session load to multiple informatica servers may improve
session performance.
Data Movement: Run the informatica server in ASCII data movement mode improves the
session performance .Because ASCII data movement mode stores a character value in one
byte .Unicode mode takes 2 bytes to store a character.
If a session joins multiple source tables in one Source Qualifier, optimizing the query may
improve performance. Also, single table select statements with an ORDER BY or
GROUP BY clause may benefit from optimization such as adding indexes.
We can improve the session performance by configuring the network packet size ,which
allows data to cross the network at one time .To do this go to server manger ,choose server
configure database connections.
If u are target consists key constraints and indexes u slow the loading of data .To improve
the session performance in this case drop constraints and indexes before u run the
session and rebuild them after completion of session.
Running parallel sessions by using concurrent batches will also reduce the time of loading
the data. So concurrent batches may also increase the session performance .
Partitioning the session improves the session performance by creating multiple connections
to sources and targets and loads data in parallel pipe lines.
In some cases if a session contains a aggregator transformation, You can use incremental
aggregation to improve session performance.
Avoid transformation errors to improve the session performance.
If the session contains lookup transformation You can improve the session performance by
enabling the look up cache.
If Ur session contains filter transformation, create that filter transformation nearer to the
sources or you can use filter condition in source qualifier.
Aggreagator, Rank and joiner transformation may often decrease the session
performance .Because they must group data before processing it. To improve session
performance in this case use sorted ports option.




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                    Informatica Questions & Answers
4) Differences between Normalizer and Normalizer transformation.

Ans)
Normalizer                                           Normalization
It is a transformation mainly using for cobol        To remove the redundancy and
sources,                                             inconsistency
it's change the rows into columns and columns
into rows
Normalizer Transformation can be used to obtain
multiple columns from a single row.

5) How do we do unit testing in Informatica?How do we load data in informatica?
Ans) Unit testing are of two types
1. Quantitaive testing
2.Qualitative testing
Steps.
1. First validate the mapping
2.Create session on the mapping and then run workflow.
Once the session is succeeded the right-click on session and go for statistics tab.
There you can see how many number of source rows is applied and how many number of
rows loaded in to targets and how many number of rows rejected. This is called Quantitative
testing.If once rows are successfully loaded then we will go for qualitative testing.
Steps
1.Take the DATM(DATM means where all business rules are mentioned to the corresponding
source columns) and check whether the data is loaded according to the DATM in to target
table. If any data is not loaded according to the DATM then go and check in the code and
rectify it.This is called Qualitative testing.This is what a developer will do in Unit Testing.

6) How do you handle decimal places while importing a flatfile into informatica?
Ans) While importing flat file definition just specify the scale for a numeric data type. In the
mapping, the flat file source supports only number data type (no decimal and integer). In
the SQ associated with that source will have a data type as decimal for that number port of
the source .
source ->number data type port ->SQ -> decimal data type .Integer is not supported.
Hence decimal is taken care. Import the field as string and then use expression to convert
it, so that we can avoid truncation if decimal places in source itself.

7) Diff between static and dynamic cache? and please explain with one example?
Ans) Difference between static and dynamic cache-

Static cache                                        Dynamic cache
   1) Once the data is cached , it will not             2) The cache is updated as to reflect
      change. example unconnected lookup                   the update in the table( or source)
      uses static cache.                                   for which it is reffering to.(ex.
                                                           connected lookup).
   3) while using a static cache in lookup we           4) but in using dynamic cache we
      can use all operators like =,<,>... while            only can use = operator
      giving condition in condition tab
   5) It is read-only cache                             6) Dynamic Cache: It is Read and
                                                           Write




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                    Informatica Questions & Answers
   7) Informatica returns value when condition         8) It will return only if condition is
      is true and if it is false it will return           false
      default value in connected look up and
      Null value in unconnected look up
   9) We can configure any static or read only         10)To cache a target table/FF src and
      cache for any lookup source.By Default              1)insert rows
      Integration service creates a static                or 2)update existing rows in the
                                                          cache
      cache.In ths it caches the lookup table,
      and when lookup condition is true it
      returns a value.

8) What is power center repository?
Ans) Standalone repository. A repository that functions individually, unrelated and
unconnected to other repositories.
Global repository. (PowerCenter only.) The centralized repository in a domain, a group of
connected repositories. Each domain can contain one global repository. The global
repository can contain common objects to be shared throughout the domain through global
shortcuts.
Local repository. (PowerCenter only.) A repository within a domain that is not the global
repository. Each local repository in the domain can connect to the global repository and use
objects in its shared folders.

Power Center repository is used to store informatica's meta data .
Information such as mapping name,location,target definitions,source
definitions,transformation and flow is stored as meta data in the repository.

9) How the informatica server sorts the string values in Ranktransformation?
Ans) We can run informatica server either in UNICODE data moment mode or ASCII data
moment mode.Unicode mode: in this mode informatica server sorts the data as per the
sorted order in session. It uses the sort order configured in session properties.
ASCII Mode:in this mode informatica server sorts the data as per the binary order

10) Is sorter an active or passive transformation?What happens if we uncheck the
distinct option in sorter.Will it be under active or passive transformation?
Ans) Sorter is an active transformation. if you don't check the distinct option it is
considered as a passive transformation. because this distinct option eliminates the duplicate
records from the table.

11) What is the difference between stop and abort

Ans) stop: In the session if u want to stop a part of batch you must stop the batch,

if the batch is part of nested batch, Stop the outer most batch

Abort:
You can issue the abort command , it is similar to stop command except it has 60 second
time out .

If the server cannot finish processing and committing data within 60 sec

12) Explain about Informatica server Architecture?




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                    Informatica Questions & Answers
Ans) Informatica Server Architecture is as above.
1. Node
2. Integration Server
3. Repository Server

13) How can you improve session performance in aggregator transformation?
Ans) There are 3 ways to improve session performance for an aggregator transformation :-

A)1)Size of data cache = Bytes required for variable columns + bytes required for output
columns.
2) Size of index cache = size of ports used in group by clause.

B) If you provide sorted data for group by ports aggregation will be faster, so for ports
which are used in group by of an aggregator sort those ports in a sorter.

C) We can use incremental aggregation if we think that there will be no change in data
which is already aggregated.

14) How can we use pmcmd command in a workflow or to run a session
Ans) pmcmd>startworkflow -f foldername workflowname

15) In update strategy target table or flat file which gives more performance ?
why?
Ans) Pros: Loading, Sorting, Merging operations will be faster as there is no index concept
and Data will be in ASCII mode.
Cons: There is no concept of updating existing records in flat file.
As there is no indexes, while lookups speed will be lesser.

16) What is the difference between filter and lookup transformation?
Ans) 1) Filter transformation is an Active transformation and Lookup is a Passive
transformation
2) Filter transformation is used to Filter rows based on condition and Lookup is used to to
look up data in a flat file or a relational table, view, or synonym

17) What are the out put files that the informatica server creates during the
session running?
Ans) Informatica server log: Informatica server(on unix) creates a log for all status and
error messages(default name: pm.server.log). It also creates an error log for error
messages.
These files will be created in informatica home directory:-

Session log file: Informatica server creates session log file for each session.It writes
information about session into log files such as initialization process,creation of sql
commands for reader and writer threads,errors encountered and load summary.The amount
of detail in session log file depends on the tracing level that you set.

Session detail file: This file contains load statistics for each targets in mapping.Session
detail include information such as table name,number of rows written or rejected.U
can view this file by double clicking on the session in monitor window

Performance detail file: This file contains information known as session performance details
which helps you where performance can be improved.To genarate this file select
the performance detail option in the session property sheet.




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                     Informatica Questions & Answers

Reject file: This file contains the rows of data that the writer does notwrite to targets.

Control file: Informatica server creates control file and a target file when you run a session
that uses the external loader.The control file contains the information about the
target flat file such as data format and loading instructios for the external loader.
Post session email: Post session email allows you to automatically communicate information
about a session run to designated recipents.You can create two different
messages.One if the session completed sucessfully the other if the session fails.

Indicator file: If you use the flat file as a target,You can configure the informatica server to
create indicator file.For each target row,the indicator file contains a number to indicate
whether the row was marked for insert,update,delete or reject.
output file: If session writes to a target file,the informatica server creates the target file
based on file prpoerties entered in the session property sheet.

Cache files: When the informatica server creates memory cache it also creates cache files.
For the following circumstances informatica server creates index and datacache files:-
Aggreagtor transformation
Joiner transformation
Rank transformation
Lookup transformation

18) How many types of dimensions are available in Informatica?
Ans) The types of dimensions available are:
1. Junk dimension
2. Degenerative Dimension
3. Conformed Dimension

19) Define informatica repository?
Ans) Infromatica Repository:The informatica repository is at the center of the informatica
suite. You create a set of metadata tables within the repository database that the
informatica application and tools access. The informatica client and server access the
repository to save and retrieve metadata.

20) How do you configure mapping in informatica
Ans) You should configure the mapping with the least number of transformations and
expressions to do the most amount of work possible. You should minimize the amount of
data moved by deleting unnecessary links between transformations.
For transformations that use data cache (such as Aggregator, Joiner, Rank, and Lookup
transformations), limit connected input/output or output ports. Limiting the number of
connected input/output or output ports reduces the amount of data the transformations
store in the data cache.
You can also perform the following tasks to optimize the mapping:
Configure single-pass reading.
Optimize datatype conversions.
Eliminate transformation errors.
Optimize transformations.
Optimize expressions.

21) How can you create or import flat file definition in to the warehouse designer?
Ans) You can not create or import flat file defintion in to warehouse designer
directly.Instead you must analyze the file in source analyzer,then drag it into the warehouse




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                    Informatica Questions & Answers
designer.
When you drag the flat file source defintion into warehouse desginer workspace,the
warehouse designer creates a relational target defintion not a file defintion.If you want to
load to a file,configure the session to write to a flat file.When the informatica server runs
the session,it creates and loads the flat file.

22) When we create a target as flat file and source as oracle.. how can i specify
first rows as column names in flat files...
Ans) use a pre sql statement....but this is a hardcoding method...if you change the column
names or put in extra columns in the flat file, you will have to change the insert statement.
You can also achive this by changing the setting in the Informatica Repository manager to
display the columns heading. The only disadvantage of this is that it will be applied on all
the files that will be generated by This server
When importing a flat file into target designer a flat file import wizard appears. In this there
is an option as 'import field names from first line'. Just check this option so integration
server treats first row values as column names.

23) Discuss the advantages & Disadvantages of star & snowflake schema?
Ans) In a STAR schema there is no relation between any two dimension tables, whereas in
a SNOWFLAKE schema there is a possible relation between the dimension tables.In star
schema there is no relationship between two relational tables. All dimensions are de-
normalized and query performence is degrades. In this snow flake schema dimensions are
normalized. In this SF schema table space is increased.Maintenence cost is high.Query
performence is increaced.

24) Difference between Rank and Dense Rank?
Ans) Rank:
1
2<--2nd position
2<--3rd position
4
5
Same Rank is assigned to same totals/numbers. Rank is followed by the Position. Golf game
ususally Ranks this way. This is usually a Gold Ranking.
Dense Rank:
1
2<--2nd position
2<--3rd position
3
4
Same ranks are assigned to same totals/numbers/names. the next rank follows the serial
number.

25) Can anyone explain error handling in Informatica with examples so that it will
be easy to explain the same in the interview.
Ans) Go to the session log file there we will find the information regarding to the
session initiation process,
errors encountered.
load summary.

so by seeing the errors encountered during the session running, we can resolve the errors.




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                    Informatica Questions & Answers
There is one file called the bad file which generally has the format as *.bad and it contains
the records rejected by informatica server. There are two parameters one fort the types of
row and other for the types of columns. The row indicators signifies what operation is going
to take place ( i.e. insertion, deletion, updation etc.). The column indicators contain
information regarding why the column has been rejected.( such as violation of not null
constraint, value error, overflow etc.) If one rectifies the error in the data preesent in the
bad file and then reloads the data in the target,then the table will contain only valid data.

26) What is the difference between connected and unconnected stored
procedures.

Ans) Unconnected:
The unconnected Stored Procedure transformation is not connected directly to the flow of
the mapping. It either runs before or after the session, or is called by an expression in
another transformation in the mapping.

connected:
The flow of data through a mapping in connected mode also passes through the Stored
Procedure transformation. All data entering the transformation through the input ports
affects the stored procedure. You should use a connected Stored Procedure transformation
when you need data from an input port sent as an input parameter to the stored procedure,
or the results of a stored procedure sent as an output parameter to another transformation.

by using unconnected stored procedure
reusability is possible
in connected only one time is possible

27) Which tasks can be performed on port level(using one specific port)?
Ans) I think unconnected Lookup or expression transformation can be used for single port
for a row.

28) What are main advantages and purpose of using Normalizer Transformation in
Informatica?
Ans) Narmalizer Transformation is used mainly with COBOL sources where most of the time
data is stored in de-normalized format. Also, Normalizer transformation can be used to
create multiple rows from a single row of data

29) What is the difference between constraind base load ordering and target load
plan

Ans) Constraint based load ordering
example:
Table 1---Master
Table 2---Detail

If the data in table1 is dependent on the data in table2 then table2 should be loaded first.In
such cases to control the load order of the tables we need some conditional loading which is
nothing but constraint based load

In Informatica this feature is implemented by just one check box at the session level.




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                    Informatica Questions & Answers
A CBl specifies the order in which data loads into the targets based on key constraints
A target load plan defines the order in which data being extracted from the source qualifier

30) What is difference between IIF and DECODE function

Ans) You can use nested IIF statements to test multiple conditions. The following example
tests for various conditions and returns 0 if sales is zero or negative:

IIF( SALES > 0, IIF( SALES < 50, SALARY1, IIF( SALES < 100, SALARY2, IIF( SALES < 200,
SALARY3, BONUS))), 0 )

You can use DECODE instead of IIF in many cases. DECODE may improve readability. The
following shows how you can use DECODE instead of IIF :

SALES > 0 and SALES < 50, SALARY1,

SALES > 49 AND SALES < 100, SALARY2,

SALES > 99 AND SALES < 200, SALARY3,

SALES > 199, BONUS)

Decode function can used in sql statement. where as if statment cant use with SQL
statement.

31) How can u work with remote database in informatica?did u work directly by
using remote connections?

Ans) To work with remote datasource u need to connect it with remote connections.But it is
not preferable to work with that remote source directly by using remote connections
.Instead u bring that source into U r local machine where informatica server resides.If u
work directly with remote source the session performance will decreases by passing less
amount of data across the network in a particular time.

32) How to import oracle sequence into Informatica.
Ans) CREATE ONE PROCEDURE AND DECLARE THE SEQUENCE INSIDE THE
PROCEDURE,FINALLY CALL THE PROCEDURE IN INFORMATICA WITH THE HELP OF STORED
PROCEDURE TRANSFORMATION.

33) Identifying bottlenecks in various components of Informatica and resolving
them.
Ans) The best way to find out bottlenecks is writing to flat file and see where the bottle
neck is .

34) What is parameter file?
Ans) For UNIX shell users, enclose the parameter file name in single quotes:
-paramfile '$PMRootDir/myfile.txt'
For Windows command prompt users, the parameter file name cannot have beginning or
trailing spaces. If the name includes spaces, enclose the file name in double quotes:
-paramfile ?$PMRootDirmy file.txt?
Note: When you write a pmcmd command that includes a parameter file located on another
machine, use the backslash () with the dollar sign ($). This ensures that the machine where




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                     Informatica Questions & Answers
the variable is defined expands the server variable.
pmcmd startworkflow -uv USERNAME -pv PASSWORD -s SALES:6258 -f east -w wSalesAvg
-paramfile '$PMRootDir/myfile.txt'

35)What is the difference between summary filter and detail filter
Ans) Summary filter can be applied on a group of rows that contain a common value.
whereas detail filters can be applied on each and every rec of the data base.

36) What is the difference between Narmal load and Bulk load?
Ans) Normal Load: Normal load will write information to the database log file so that if any
recorvery is needed it is will be helpful. when the source file is a text file and loading data to
a table,in such cases we should you normal load only, else the session will be failed.

Bulk Mode: Bulk load will not write information to the database log file so that if any
recorvery is needed we can't do any thing in such cases.

compartivly Bulk load is pretty faster than normal load.

37) How u will create header and footer in target using informatica?
Ans) If you are focus is about the flat files then one can set it in file properties while
creating a mapping or at the session level in session properties

38) What are two types of processes that informatica runs the session?
Ans) Load manager Process: Starts the session, creates the DTM process, and sends post-
session email when the session completes.
The DTM process. Creates threads to initialize the session, read, write, and transform data,
and handle pre- and post-session operations.

39) What r the types of groups in Router transformation?
Ans) A Router transformation has the following types of groups:

Input
Output
Input Group
The Designer copies property information from the input ports of the input group to create a
set of output ports for each output group.

Output Groups
There are two types of output groups:

User-defined groups
Default group
You cannot modify or delete output ports or their properties.

40) What are the real time problems generally come up while doing/running
mapping/any transformation?can any body explain with example.
Ans) Here are few real time examples of problems while running informatica mappings:

1) Informatica uses OBDC connections to connect to the databases.
The database passwords (production ) is changed in a periodic
manner and the same is not updated at the Informatica side.
Your mappings will fail in this case and you will get database connectivity error.
2) If you are using Update strategy transformation in the mapping, in the session properties




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                    Informatica Questions & Answers
you have to select Treat Source Rows : Data Driven. If we do not select this Informatica
server will ignore updates and it only Inserts rows.
3) If we have mappings loading multiple target tables we have to provide the Target Load
Plan
in the sequence we want them to get loaded.
4) Error:Snapshot too old is a very common error when using Oracle tables. We get this
error
while using too large tables. Idealy we should schelude these loads when server is not very
busy (meaning when no other loads are running).
5) We might get some poor performance issues while reading from large tables. All the
source tables
should be indexed and updated regularly.

41) What is difference between maplet and reusable transformation?
Ans) mapplet:-
--contains input and output transformations.
--designed in mapplet designer.
--reusable.
--contains multiple transformations.
--we use it to reuse multiple tr for a task to be done.

Reusable transformation:-
--no input and output transformation is needed.
--designed in mapping designer.
--reusable.
--It is a singl transformation
--we create it to reuse a single transformation in future

42) How many types of facts and what are they?
Ans) There are
Factless Facts:Facts without any measures.
Additive Facts:Fact data that can be additive/aggregative.
Non-Additive facts: Facts that are result of non-additon
Semi-Additive Facts: Only few colums data can be added.
Periodic Facts: That stores only one row per transaction that happend over a period of time.
Accumulating Fact: stores row for entire lifetime of event.

43) what are load types in informatica and what is delta load
Ans) There are two types of load i) Normal Load ii) Bulk Load
Normal Load-
The integration service writes to the database log then it enters into target.
a)performance of loading to target decreases but session recovery occurs.
b)Rollback and commit possible
Bulk Load:
The integration service bypasses the database log without writing into it and directly loaded
into target.
a)Performance increases but session recovery doesnot occur.
b) Rollback and commit also not possible.
In bulk loading we need to consider the following:
1)Without creating any primary and foreign key at database level but however in target
definition.
2)drop index before loading into target and create index after loading.
3)disable enable parallel mode option




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                    Informatica Questions & Answers

44) What are the session parameters?
Ans) Session parameters are like maping parameters,represent values you might want to
change between sessions such as database connections or source files.
Server manager also allows you to create userdefined session parameters.Following are
user defined session parameters:-
Database connections
Source file names: use this parameter when you want to change the name or location of
session source file between session runs.
Target file name : Use this parameter when you want to change the name or location of
session target file between session runs.
Reject file name : Use this parameter when you want to change the name or location of
session reject files between session runs.By using Session parameters we can reuse the
session how many times you want. The main purpose of session parameter it represents
connection path to a database system. we can reuse the different types of databases.
If you want to use session parameter we have to follow the following procedure
1. Double click the session and select mapping tab in the mapping tab select target
connection, in the target connection select writer property click on Radio Button USE
Connection Variable and write the connection variable $$<Connection Variable>.
After that create a parameter file with .txt or .prm using the following syntax
[folder.session]
$$<Connection Variable=<databse name>

45) What are the methods for creating reusable transforamtions?
Ans) Two methods:-
1.Design it in the transformation developer.
2.Promote a standard transformation from the mapping designer.After you add a
transformation to the mapping , You can promote it to the status of reusable
transformation.
Once you promote a standard transformation to reusable status,You can demote it to a
standard transformation at any time.
If you change the properties of a reusable transformation in mapping,You can revert it to
the original reusable transformation properties by clicking the revert button.

46) What does the expression n filter transformations do in Informatica Slowly
growing target wizard?
Ans) Filter transformation filters the rows that are not flagged and passes the flagged rows
to the Update strategy transformation

EXP is used to perform record level operations and is a passive transformation.
like op_col1=ip_col1*10+ip_col2
for all the records same operation will be performed on values of 2 i/p fields -
ip_col1,ip_col2 and o/p will pass through o/p field-op_col1
FIL is used to filter some records based on any condition.(the way we write condition in
where clause,we can simply put the condition in FIL transformation)...records not matching
the condition will be DROPPED(not rejected)from the mapping flow and there is no way to
capture dropped rows(unlike rejected rows in UPD can be captured in reject file iff forward
reject rows option is not ticked)...so FIL is activetransformation...
FIL-Filter Transformation
EXP-Expression Transformation
UPD-Update Strategy Transformation




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                     Informatica Questions & Answers
47) Where to store informatica rejected data? How to extract the informatica
rejected data ?
Ans) The reject rows say for example due to unique key constrain is all pushed by session
into the $PMBadFileDir (default relative path is
<INFA_HOME/PowerCenter/server/infa_shared/BadFiles) which is configured with path at
Integration Service level. Every Target will have property saying Reject filename which
gives the file in which rejects rows are stored.

48)How to use the unconnected lookup i.e., from where the input has to be taken
and the output is linked? What condition is to be given?
Ans) The unconnected lookup is used just like a function call. in an expression
output/variable port or any place where an expression is accepted(like condition in update
strategy etc..), call the unconnected lookup...something like :LKP.lkp_abc(input_port).......
(lkp_abc is the name of the unconnected lookup...(plz check the exact syntax)).....give the
input value just like we pass parameters to functions, and it'll return the output after
looking up.

49) What is the Rankindex in Ranktransformation?
Ans) The Designer automatically creates a RANKINDEX port for each Rank transformation.
The Informatica Server uses the Rank Index port to store the ranking position for<br>each
record in a group. For example, if you create a Ranktransformation that ranks the top 5
salespersons for each quarter, the rank index numbers the salespeople from 1<br>to 5.

50) What is difference between partioning of relatonal target and partitioning of
file targets?
Ans) Partition's can be done on both relational and flat files.
Informatica supports following partitions
1.Database partitioning
2.RoundRobin
3.Pass-through
4.Hash-Key partitioning
5.Key Range partitioning
All these are applicable for relational targets.For flat file only database partitioning is not
applicable.
Informatica supports Nway partitioning.U can just specify the name of the target file and
create the partitions, rest will be taken care by informatica session.

51) Why did u use update stategy in your application?
Ans) Update Strategy is used to drive the data to be Inert, Update and Delete depending
upon some condition. You can do this on session level tooo but there you cannot define any
condition.For eg: If you want to do update and insert in one mapping...you will create two
flows and will make one as insert and one as update depending upon some condition.Refer :
Update Strategy in Transformation Guide for more information

52) What is IQD file?
Ans) IQD file is nothing but Impromptu Query Definetion,This file is maily used in Cognos
Impromptu tool after creating a imr( report) we save the imr as IQD file which is used while
creating a cube in power play transformer.In data source type we selectImpromptu Query
Definetion.

53) What r the mapings that we use for slowly changing dimension table?




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                     Informatica Questions & Answers
Ans) We can use the following Mapping for slowly Changing dimension table.

?   Expression
?   Lookup
?   Filter
?   Sequence Generator
?   Update Strategy

54) How do I import VSAM files from source to target. Do I need a special plugin
Ans) As far my knowledge by using power exchange tool convert vsam file to oracle tables
then do mapping as usual to the target table.

55) What is meant by aggregate fact table and where is it used?
Ans) Basically fact tables are two kinds 1. Aggregated factable and Factless fact table.
Agregated factable has aggregarted columns. for eg. Total-Sal, Dep-Sal. where as in
factless factable will not have aggregated colums and it only has FK to the Dimension
tables.

56) What are Target Types on the Server?
Ans) Target Types are File, Relational and ERP.

57) What are mapping parameters and varibles in which situation we can use it
Ans) If we need to change certain attributes of a mapping after every time the session is
run, it will be very difficult to edit the mapping and then change the attribute. So we use
mapping parameters and variables and define the values in a parameter file. Then we could
edit the parameter file to change the attribute values. This makes the process simple.
Mapping parameter values remain constant. If we need to change the parameter value then
we need to edit the parameter file .
But value of mapping variables can be changed by using variable function. If we need to
increment the attribute value by 1 after every session run then we can usemapping
variables .
In a mapping parameter we need to manually edit the attribute value in the parameter file
after every session run.

58) How do you create single lookup transformation using multiple tables?
Ans) Write a override sql query. Adjust the ports as per the sql query.

59) Why is meant by direct and indirect loading options in sessions?
Ans) when we use multiple source files, we create a file containing the names and
directories of each source file we want the PowerCenter Server to use. This file is referred to
as a file list.

when configuring the session properties,choose Indirect in the Source Filetype field,enter
the file name of the file list in the Source Filename field and enter the location of the file list
in the Source File Directory field. When the session starts, thePowerCenter Server reads the
file list, then locates and reads the first file source in the list. After the PowerCenter Server
reads the first file, it locates and reads the next file in the list.

60) What are Target Options on the Servers?
Ans) Target Options for File Target type are FTP File, Loader and MQ.
There are no target options for ERP target type.
Target Options for Relational are Insert, Update (as Update), Update (as Insert), Update
(else Insert), Delete, and Truncate Table.




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                    Informatica Questions & Answers

61) what are the difference between view and materialized view?
Ans) Materialized views are schema objects that can be used to summarize, precompute,
replicate, and distribute data. E.g. to construct a data warehouse.

A materialized view provides indirect access to table data by storing the results of a query in
a separate schema object. Unlike an ordinary view, which does not take up any storage
space or contain any data

62) To achieve the session partition what are the necessary tasks you have to do?
Ans) Configure the session to partition source data.
Install the informatica server on a machine with multiple CPU?s.

63) On a day, I load 10 rows in my target and on next day if I get 10 more rows to
be added to my target out of which 5 are updated rows how can I send them to
target? How can I insert and update the record?
Ans) We can achieve this task by SCD(slowly changing dimensions) type 1.

1. have a lookup on target and check for the primary key values, if the record is new, insert
the record and if the record has changed, then update the record.
2. for this u have to create a update strategy transformation inside the mapping.

64) Can you generate reports in Informatcia?

Ans) Yes. By using Metadata reporter we can generate reports in informatica.Informatica is
tool to support data extracting ,transforming and loading.i am not sure informatica support
for reporting.my experience is concern informatica doesn't support reporting.

65) Explain use of update strategy transformation
Ans) This is the important transformation,is used to maintain the history data or just most
recent changes into the target table.
We can set or flag the records by using these two levels.
1) Within a session:
When you configure the session,you can instruct the informatica server to either treat all
the records in the same way.
2) Within a mapping:
within a mapping we use update strategy transformation to flag the records like
insert,update,delete or reject.

66) The designer includes a "Find" search tool as part of the standard tool bar.
What can it be used to find?
Ans) Search for two things:

1. Transformations
2. Ports in the Transformation

67) If you have four lookup tables in the workflow. How do you troubleshoot to
improve performance?

Ans) There r many ways to improve the mapping which has multiple lookups.
1) we can create an index for the lookup table if we have permissions(staging area).
2) divide the lookup mapping into two (a) dedicate one for insert means: source - target,,
these r new rows . only the new rows will come to mapping and the process will be fast . (b)




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                    Informatica Questions & Answers
dedicate the second one to update : source=target,, these r existing rows. only the rows
which exists allready will come into the mapping.
3)we can increase the chache size of the lookup.

68) How to recover sessions in concurrent batches?
Ans) If multiple sessions in a concurrent batch fail, you might want to truncate all targets
and run the batch again. However, if a session in a concurrent batch fails and the rest of
the sessions complete successfully, you can recover the session as a standalone session.
To recover a session in a concurrent batch:
1.Copy the failed session using Operations-Copy Session.
2.Drag the copied session outside the batch to be a standalone session.
3.Follow the steps to recover a standalone session.
4.Delete the standalone copy.

69) Briefly explian the Versioning Concept in Power Center 7.1.
Ans) When you create a version of a folder referenced by shortcuts, all shortcuts continue
to reference their original object in the original version. They do not automatically update to
the current folder version.

For example, if you have a shortcut to a source definition in the Marketing folder, version
1.0.0, then you create a new folder version, 1.5.0, the shortcut continues to point to the
source definition in version 1.0.0.

Maintaining versions of shared folders can result in shortcuts pointing to different versions
of the folder. Though shortcuts to different versions do not affect the server, they might
prove more difficult to maintain. To avoid this, you can recreate shortcuts pointing to earlier
versions, but this solution is not practical for much-used objects. Therefore, when possible,
do not version folders referenced by shortcuts.

70) Why we use lookup transformations?
Ans) Get a related value-Get the Employee Name from Employee table based on the
Employee IDPerform Calculation.
Update slowly changing dimension tables - We can use unconnected lookup transformation
to determine whether the records already exist in the target or not.

71) What is Datadriven?
Ans) The informatica server follows instructions coded into update strategy transformations
with in the session maping determine how to flag records for insert, update, delete or
reject. If you do not choose data driven option setting,the informatica server ignores all
update strategy transformations in the mapping.If the data driven option is selected in the
session properties,it follows the instructions in the update strategy
transformation in the mapping o.w it follows instuctions specified in the session.

72) What is batch and describe about types of batches?
Ans) Batch--- is a group of any thing

Different batches ----Different groups of different things.
There are two types of batches
1. Concurrent
2. Sequential

73) Can Informatica be used as a Cleansing Tool? If Yes, give example of
transformations that can implement a data cleansing routine.




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                     Informatica Questions & Answers
Ans) Yes, we can use Informatica for cleansing data. some time we use stages to cleansing
the data. It depends upon performance again else we can use expression to cleasing data.

For example an feild X have some values and other with Null values and assigned to target
feild where target feild is notnull column, inside an expression we can assign space or some
constant value to avoid session failure.

The input data is in one format and target is in another format, we can change the format in
expression.

we can assign some default values to the target to represent complete set of data in the
target.

74) Differences between connected and unconnected lookup?
Ans) Connected lookup:-
1> Receives input values diectly from the pipe line.
2> You can use a dynamic or static cache.
3> Cache includes all lookup columns used in the maping.
4> Support user defined default values.

Unconnected lookup:-
1> Receives input values from the result of a lkp expression in a another transformation.
2> You can use a static cache.
3> Cache includes all lookup out put ports in the lookup condition and the lookup/return
port.
4> Does not support user defiend default values.

75) How to read rejected data or bad data from bad file and reload it to target?
Ans) Correction the rejected data and send to target relational tables using loadorder
utility. Find out the rejected data by using column indicatior and row indicator.

76) What are the various test procedures used to check whether the data is loaded
in the backend, performance of the mapping, and quality of the data loaded in
INFORMATICA. 2) What are the common problems developers face while ETL
development
Ans) If you want to know the performance of a mapping at transformation level, then select
the option in the session properties-> collect performance data. At the run time in the
monitor you can see it in the?performance tab or you can get it from a file.

The PowerCenter Server names the file session_name.perf, and stores it in the same
directory as the session log. If there is no session-specific directory for the session log,
thePowerCenter Server saves the file in the default log files directory.

Quality of the data loaded depends on the quality of data in the source. If cleansing is
required then have to perform some data cleansing operations in informatica. Final data will
always be clean if followed.

77) What are the types of data that passes between informatica server and stored
procedure?

Ans) Three types of data:-
Input/Out put parameters




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                    Informatica Questions & Answers
Return Values
Status code.

78) What are the types of metadata that stores in repository?
Ans) Following are the types of metadata that stores in the repository:-
Database connections
Global objects
Mappings
Mapplets
Multidimensional metadata
Reusable transformations
Sessions and batches
Short cuts
Source definitions
Target defintions
Transformations.

79) How to move the mapping from one database to another?
Ans) 1.? Open the mapping you want to migrate.? Go to File Menu - Select 'Export Objects'
and give a name - an XML file will be generated.? Connect to the repository where you want
to migrate and then select File Menu - 'Import Objects' and select theXML file name.

2.? Connect to both the repositories.??Go to the source folder and select mapping name
from the?object navigator and select?'copy' from 'Edit' menu.? Now, go to the target folder
and select 'Paste' from 'Edit' menu.? Be sure you open the target folder.

80) What is the target load order?
Ans) The Integration Service reads sources in a target load order group concurrently, and it
processes target load order groups sequentially.
To specify the order in which the Integration Service sends data to targets, create one
source qualifier for each target within a mapping. To set the target load order, you then
determine in which order the Integration Service reads each source in the mapping.

To set the target load order:
1.Create a mapping that contains multiple target load order groups.
2.Click Mappings > Target Load Plan.
The Target Load Plan dialog box lists all Source Qualifier transformations in the mapping
and the targets that receive data from each source qualifier.
3.Select a source qualifier from the list.
4.Click the Up and Down buttons to move the source qualifier within the load order.
5.Repeat steps 3 to 4 for other source qualifiers you want to reorder.
6.Click OK.

81) Can we eliminate duplicate rows by using filter and router transformation ?if
so explain me in detail .

Ans) U can use SQL query for uniqness if the source is Relational

But if the source is Flat file then u should use Shorter or Aggregatot transformation

82) What is parameter file?
Ans) Parameter file is to define the values for parameters and variables used in a session.A
parameter




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                    Informatica Questions & Answers
file is a file created by text editor such as word pad or notepad.
You can define the following values in parameter file:-
Maping parameters
Maping variables
session parameters.

83) Can you use the maping parameters or variables created in one maping into
another maping?
Ans) No

84) How do u check the source for the latest records that are to be loaded into the
target. i.e i have loaded some records yesterday, today again the file has been
populated with some more records today, so how do i find the records populated
today.
Ans) a) Create a lookup to target table from Source Qualifier based on primary Key.
b) Use and expression to evaluate primary key from target look-up. ( If a new source record
look-up primary key port for target table should return null). Trap this with decode and
proceed.

85) What is the default join that source qualifier provides?
Ans) Inner equi join. cross join

86) Why did you use stored procedure in your ETL Application?
Ans) usage of stored procedure has the following advantages
1) checks the status of the target database
2) drops and recreates indexes
3) determines if enough space exists in the database
4) performs aspecilized calculation

87) What is the diff b/w Stored Proc (DB level) & Stored proc trans
(INFORMATICA level) ? again why should we use SP trans ?
Ans) Stored Procedure tr:-
===========
In database :-
we execute it using "EXECUTE ST_PRO_NAME" command
In Informatica:-
when we create stored procedure tr it contains a return port by default.
this port is already assigned to the st pro which we selected while creating this tr.
just we need to connect it to output port in target and connect input ports to it.

Uses:-
1)used to populate and maintain database.
2)allow user defined variables, conditional statements and other powerful programmimg
features.
3)very useful as they are flexible than SQL statements.
4)provide error handling and logging necessary for critical tasks.
5)used for many other tasks.


88) What is difference between stored procedure transformation and external
procedure transformation?
Ans) In case of storedprocedure transformation procedure will be compiled and executed in
a relational data source.U need data base connection to import the stored procedure




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                    Informatica Questions & Answers
in to u?r maping.Where as in external procedure transformation procedure or function will
be executed out side of data source.Ie u need to make it as a DLL to access in u r
maping.No need to have data base connection in case of external procedure transformation.

89) What is the procedure to load the fact table.Give in detail?
Ans) your business needs. For the fact table, you need a primary key so use a sequence
generator transformation to generate a unique key and pipe it to the target (fact) table with
the foreign keys from the source tables.

90) What is the status code?
Ans) Status code provides error handling for the informatica server during the session.The
stored procedure issues a status code that notifies whether or not stored procedure
completed sucessfully.This value can not seen by the user.It only used by the informatica
server to determine whether to continue running the session or stop.

91) What are variable ports and list two situations when they can be used?
Ans) We have mainly tree ports Inport, Outport, Variable port. Inport represents data is
flowing into transformation. Outport is used when data is mapped to next transformation.
Variable port is used when we mathematical calculations are required. If any addition i will
be more than happy if you can share.We can use variable ports to store values of previous
records which is not otherwise possible in Informatica.

92) While importing the relational source defintion from database, what are the
meta data of source you import?
Ans) Source name
Database location
Column names
Datatypes
Key constraints.

93) What is Transaction?
Ans) A transaction can be define as DML operation.

means it can be insertion,modification or deletion of data performed by users/
analysts/applicators
Transaction is a logical unit of work that comprises one or more sql statements executed by
a single user

94) How can you access the remote source into your session?
Ans) Relational source: To acess relational source which is situated in a remote place ,u
need to configure database connection to the datasource.
FileSource : To access the remote source file you must configure the FTP connection to the
host machine before you create the session.
Hetrogenous : When U?r maping contains more than one source type,the server manager
creates a hetrogenous session that displays source options for all types.

95) What are the basic needs to join two sources in a source qualifier?
Ans) Basic need to join two sources using source qualifier:
1) Both sources should be in same database
2) The should have at least one column in common with same data types

96) What are the diffrence between joiner transformation and source qualifier
transformation?




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                     Informatica Questions & Answers
Ans) Joiner Transformation can be used to join tables from hetrogenious (different
sources), but we still need a common key from both tables. If we join two tables without a
common key we will end up in a Cartesian Join. Joiner can be used to join tables from
difference source systems where as Source qualifier can be used to join tables in the same
database.
We definitely need a common key to join two tables no mater they are in same database or
difference databases.

97) With out using Updatestretagy and sessons options, how we can do the
update our target table?
Ans) n the target definition there is an option to write the update override query, here we
can specify the update query and this will update the rows.

98) What are the types of maping in Getting Started Wizard?
Ans) Simple Pass through maping :
Loads a static fact or dimension table by inserting all rows. Use this mapping when you
want to drop all existing data from your table before loading new data.
Slowly Growing target :
Loads a slowly growing fact or dimension table by inserting new rows. Use this mapping to
load new data when existing data does not require updates.

99) in the concept of mapping parameters and variables, the variable value will be
saved to the repository after the completion of the session and the next time when
u run the session, the server takes the saved variable value in the repository and
starts assigning the next value of the saved value. for example i ran a session and
in the end it stored a value of 50 to the repository.next time when i run the
session, it should start with the value of 70. not with the value of 51. how to do
this.
Ans) u can do one thing after running the mapping,, in workflow manager

start-------->session.

right clickon the session u will get a menu, in that go for persistant values, there u will find
the last value stored in the repository regarding to mapping variable. then remove it and
put ur desired one, run the session... i hope ur task will be done

100) What are the joiner caches?
Ans)
master rows.
After building the caches, the Joiner transformation reads records from the detail source
and perform joins.

101) What transformation you can use inplace of lookup?
Ans) Look-up transformation can serve in so many situations.
So, if you can a bit particular about the scenarioo that you are talking about, it will be easy
to interpret.

102) How to define Informatica server?
Ans) Informatica server is the main server component in informatica product family..Which
is resonsible for reads the data from various source system and tranforms the data
according to business rule and loads the data into the target table

103) How can u complete unrcoverable sessions?




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                    Informatica Questions & Answers
Ans) Under certain circumstances, when a session does not complete, you need to truncate
the target tables and run the session from the beginning. Run the session from the
beginning when the Informatica Server cannot run recovery or when running recovery
might result in inconsistent data.

104) How to lookup the data on multiple tabels.
Ans) if the two tables are relational, then u can use the SQL lookup over ride option to join
the two tables in the lookup properties.u cannot join a flat file and a relatioanl table.

eg: lookup default query will be select lookup table column_names from lookup_table. u can
now continue this query. add column_names of the 2nd table with the qualifier, and a where
clause. if u want to use a order by then use -- at the end of the order by.

105) What is the default source option for update stratgey transformation?
Ans) default option for update stratgey t/r is dd_insert or we can put '0'.
in session level data driven

106)What is pushdown optimizations in pc 8.x with example?
Ans) Use pushdown optimization to push transformation logic to the source or target
database. The Integration Service analyzes the transformation logic, mapping, and session
configuration to determine the transformation logic it can push to the database. At run time,
the IntegrationService executes any SQL statement generated against the source or target
tables, and it processes any transformation logic that it cannot push to the database.
Select one of the following values:
- None. The Integration Service does not push any transformation logic to the database.

- To Source. The Integration Service pushes as much transformation logic as possible to the
source database.

- To Target. The Integration Service pushes as much transformation logic as possible to the
target database.

- Full. The Integration Service pushes as much transformation logic as possible to both the
source database and target database.

- $$PushdownConfig. The $$PushdownConfig mapping parameter allows you to run the
same session with different pushdown optimization configurations at different times. For
more information about configuring the $$PushdownConfig mapping parameter and
parameter file, see Using the $$PushdownConfig Mapping Parameter.

107) In a scenario I have col1, col2, col3, under that 1,x,y, and 2,a,b and I want in
this form col1, col2 and 1,x and 1,y and 2,a and 2,b, what is the procedure?
Ans) Use Normalizer :
create two ports -
first port occurs = 1
second make occurs = 2
two output ports are created and
connect to target

108) If u had to split the source level key going into two seperate tables. One as
surrogate and other as primary. Since informatica does not gurantee keys are
loaded properly(order!) into those tables. What are the different ways you could
handle this type of situation?




                                             35
                     Informatica Questions & Answers
Ans) foreign key

109) What are the transformations that restricts the partitioning of sessions? Ans)
Advanced External procedure tranformation and External procedure transformation: This
transformation contains a check box on the properties tab to allow partitioning.
Aggregator Transformation: If u use sorted ports You can not parttion the assosiated source
Joiner Transformation : You can not partition the master source for a joiner transformation
Normalizer Transformation
XML targets.

POWER EXCHANGE SOURCE and TARGETS
Advanced External procedure tranformation and External procedure transformation: This
transformation contains a check box on the properties tab to allow partitioning.
Aggregator Transformation: If u use sorted ports You can not parttion the assosiated source
Joiner Transformation : You can not partition the master source for a joiner transformation
Normalizer Transformation
XML targets.


110) Can u explain one critical mapping? 2.performance issue which one is better?
whether connected lookup tranformation or unconnected one?

Ans) it depends on your data and the type of operation u r doing.

If u need to calculate a value for all the rows or for the maximum rows coming out of the
source then go for a connected lookup.

Or,if it is not so then go for unconnectd lookup.

Specially in conditional case like,

we have to get value for a field 'customer' from order tabel or from customer_data table,on
the basis of following rule:

If customer_name is null then ,customer=customer_data.ustomer_Id

otherwise

customer=order.customer_name.

so in this case we will go for unconnected lookup

Dimesions are
1.SCD
2.Rapidly changing Dimensions
3.junk Dimensions
4.Large Dimensions
5.Degenerated Dimensions
6.Conformed Dimensions.

111) What is hash table informatica?




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                    Informatica Questions & Answers
Ans) In hash partitioning, the Informatica Server uses a hash function to group rows of
data among partitions. The Informatica Server groups the data based on a partition key.Use
hash partitioning when you want the Informatica Server to distribute rows to the partitions
by group. For example, you need to sort items by item ID, but you do not know how many
items have a particular ID number.

112) In a joiner transformation, you should specify the source with fewer rows as
the master source. Why?
Ans) Joiner transformation compares each row of the master source against the detail
source. The fewer unique rows in the master, the fewer iterations of the join comparison
occur, which speeds the join process.Joiner Transformation will cache Master table's data
hence it is advised to define table with less #of rows as master.

113) what is difference between lookup cashe and unchashed lookup? Can i run
the mapping with out starting the informatica server?
Ans) The difference between cache and uncacheed lookup iswhen you configure the lookup
transformation cache lookup it stores all the lookup table data in the cache when the first
input record enter into the lookup transformation, in cache lookup the select statement
executes only once and compares the values of the input record with the values in the
cachebut in uncache lookup the the select statement executes for each input record
entering into the lookup transformation and it has to connect to database each time
entering the new record

114) What are the tasks that Loadmanger process will do?
Ans) Manages the session and batch scheduling: Whe you start the informatica server the
load maneger launches and queries the repository for a list of sessions configured to run
on the informatica server.When you configure the session the loadmanager maintains list of
list of sessions and session start times.When you sart a session loadmanger fetches the
session information from the repository to perform the validations and verifications prior to
starting DTM process.

Locking and reading the session: When the informatica server starts a session lodamaager
locks the session from the repository.Locking prevents you starting the session again and
again.

Reading the parameter file: If the session uses a parameter files,loadmanager reads the
parameter file and verifies that the session level parematers are declared in the file
Verifies permission and privelleges: When the sesson starts load manger checks whether or
not the user have privelleges to run the session.

Creating log files: Loadmanger creates logfile contains the status of session.

115) How can we join the tables if the tables have no primary and forien key
relation and no matchig port to join?
Ans) without common column or common data type we can join two sources using dummy
ports.

1.Add one dummy port in two sources.
2.In the expression trans assing '1' to each port.
2.Use Joiner transformation to join the sources using dummy port(use join conditions).

116) In a sequential Batch how can we stop single session?




                                              35
                    Informatica Questions & Answers
Ans) We can stop it using PMCMD command or in the monitor right click on that perticular
session and select stop.this will stop the current session and the sessions next to it.

117) How to create the staging area in your database
Ans) A Staging area in a DW is used as a temporary space to hold all the records from the
source system. So more or less it should be exact replica of the source systems except for
the laod startegy where we use truncate and reload options.

So create using the same layout as in your source tables or using the Generate SQL option
in the Warehouse Designer tab.

118) What is the logic will you implement to laod the data in to one factv from 'n'
number of dimension tables.
Ans) Noramally evey one use

!)slowly changing diemnsions

2)slowly growing dimensions

119) What r the basic needs to join two sources in a source qualifier?
Ans) The both the table should have a common field with same data type.
Its not necessary both should follow primary and foreign relationship. If any relation ship
exists that will help u in performance point of view.The two sources should be a relational
and homogeneous

120) What are various types of Aggregation?
Ans) Various types of aggregation are SUM, AVG, COUNT, MAX, MIN, FIRST, LAST,
MEDIAN, PERCENTILE, STDDEV, and VARIANCE.

121) If you want to create indexes after the load process which transformation
you choose?
Ans) Its usually not done in the mapping(transformation) level. Its done in session level.
Create a command task which will execute a shell script (if Unix) or any other scripts which
contains the create index command. Use this command task in the workflow after the
session or else, You can create it with a post session command.

122) How the informatica server increases the session performance through
partitioning the source?
Ans) For a relational sources informatica server creates multiple connections for each
parttion of a single source and extracts seperate range of data for each connection.
Informatica server reads multiple partitions of a single source concurently.Similarly for
loading also informatica server creates multiple connections to the target and loads
partitions of data concurently.
For XML and file sources,informatica server reads multiple files concurently.For loading the
data informatica server creates a seperate file for each partition(of a source file). You can
choose to merge the targets.

123) How can you improve the performance of Aggregate transformation?
Ans) we can improve the agrregator performence in the following ways

1.send sorted input.
2.increase aggregator cache size.i.e Index cache and data cache.




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                    Informatica Questions & Answers
3.Give input/output what you need in the transformation.i.e reduce number of input and
output ports.

Use Sorter Transformation to sort input in aggregrator properties
filter the records before

124) What r the unsupported repository objects for a mapplet?
Ans) Source definitions. Definitions of database objects (tables, views, synonyms) or files
that provide source data.
Target definitions. Definitions of database objects or files that contain the target data.
Multi-dimensional metadata. Target definitions that are configured as cubes and
dimensions.
Mappings. A set of source and target definitions along with transformations containing
business logic that you build into the transformation. These are the instructions that the
Informatica Server uses to transform and move data.
Reusable transformations. Transformations that you can use in multiple mappings.
Mapplets. A set of transformations that you can use in multiple mappings.
Sessions and workflows. Sessions and workflows store information about how and when the
Informatica Server moves data. A workflow is a set of instructions that describes how and
when to run tasks related to extracting, transforming, and loading data. A session is a type
of task that you can put in a workflow. Each session corresponds to a single mapping.

125) What r the types of lookup caches?
Ans) 1)Static Cache
2)Dynamic Cache
3)Persistent Cache
4)Reusable Cache
5)Shared Cache

126) What r the tasks that source qualifier performs?
Ans) Join data originating from the same source database. You can join two or more tables
with primary-foreign key relationships by linking the sources to one Source Qualifier.
Filter records when the Informatica Server reads source data. If you include a filter
condition, the Informatica Server adds a WHERE clause to the default query.
Specify an outer join rather than the default inner join. If you include a user-defined join,
the Informatica Server replaces the join information specified by the metadata in the SQL
query.
Specify sorted ports. If you specify a number for sorted ports, the Informatica Server adds
an ORDER BY clause to the default SQL query.
Select only distinct values from the source. If you choose Select Distinct, the Informatica
Server adds a SELECT DISTINCT statement to the default SQL query.
Create a custom query to issue a special SELECT statement for the Informatica Server to
read source data. For example, you might use a custom query to perform aggregate
calculations or execute a stored procedure.

127) If a session fails after loading of 10,000 records in to the target.How can u
load the records from 10001 th record when u run the session next time in
informatica 6.1?
Ans) Running the session in recovery mode will work, but the target load type should be
normal. If its bulk then recovery wont work as expected

128) Why dimenstion tables are denormalized in nature ?




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                     Informatica Questions & Answers
Ans) Because in Data warehousing historical data should be maintained, to maintain
historical data means suppose one employee details like where previously he worked, and
now where he is working, all details should be maintain in one table, if u maintain primary
key it won't allow the duplicate records with same employee id. so to maintain historical
data we are all going for concept data warehousing by using surrogate keys we can achieve
the historical data(using oracle sequence for critical column).
so all the dimensions are marinating historical data, they are de normalized, because of
duplicate entry means not exactly duplicate record with same employee number another
record is maintaining in the table.

129) What is polling?
Ans) It displays the updated information about the session in the monitor window. The
monitor window displays the status of each session when you poll the informatica server.

130) In which condtions we can not use joiner transformation(Limitaions of joiner
transformation)?

Ans) Both pipelines begin with the same original data source.
Both input pipelines originate from the same Source Qualifier transformation.
Both input pipelines originate from the same Normalizer transformation.
Both input pipelines originate from the same Joiner transformation.
Either input pipelines contains an Update Strategy transformation.
Either input pipelines contains a connected or unconnected Sequence Generator
transformation.


131) What r the active and passive transforamtions?
Ans) Transformations can be active or passive. An active transformation can change the
number of rows that pass through it, such as a Filter transformation that removes rows that
do not meet the filter condition.

A passive transformation does not change the number of rows that pass through it, such as
an Expression transformation that performs a calculation on data and passes all rows
through the transformation.

132) What is the maplet?

Ans) Maplet is a set of transformations that you build in the maplet designer and You can
use in multiple mapings.

A Mapplet is a reusable object defined with business logic using set of transformations. It is
created using Mapplet designer tool.

133) What is surrogatekey ? In ur project in which situation u has used ? explain
with example ?

Ans)    A surrogate key is system genrated/artificial key /sequence number or A surrogate key is a
substitution for the natural primary key.It is just a unique identifier or number for each row that
can be used for the primary key to the table. The only requirement for a surrogate primary key is
that it is unique for each row in the tableI it is useful because the natural primary key (i.e.
Customer Number in Customer table) can change and this makes updates more difficult.but In




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                      Informatica Questions & Answers

my project, I felt that the primary reason for the surrogate keys was to record the changing
context of the dimension attributes.(particulaly for scd )The reason for them being integer and
integer joins are faster. Unlike other


134) Partitioning, Bitmap Indexing (when to use), how will the bitmap indexing
will effect the performance
Ans) Bitmap indexing a indexing technique to tune the performance of SQL queries.
The default type is B-Tree indexers which is of high cardinality (normalized data).
You can use bitmap indexers for de-normalized data or low cardinalities. The
condition is the amount of DISTINCT rows should be less than 4% of the total rows.
If it satisfies the given condition then bitmap indexers will optimize the performance
for this kind of tables.

135) What is difference between dimention table and fact table and what are
different dimention tables and fact tables

Ans)   In the fact table contain measurable data and less columns and meny rows,

It's contain primarykey

Diffrent types of fact tables:

additive,non additive, semi additive

In the dimensions table contain textual descrption of data and also contain meny columns,less
rows

Its contain primary key

Both contains primary keys
Fact tables are which are measurable and have less columns and more rows
But in dimension which are not measurable


136) What are cost based and rule based approaches and the difference
Ans) Cost based and rule based approaches are the optimization techniques which
are used in related to databases, where we need to optimize a sql query.
Basically Oracle provides Two types of Optimizers (indeed 3 but we use only these
two techniques., bcz the third has some disadvantages.)
When ever you process any sql query in Oracle, what oracle engine internally does
is, it reads the query and decides which will the best possible way for executing the
query. So in this process, Oracle follows these optimization techniques.
1. cost based Optimizer(CBO): If a sql query can be executed in 2 different ways
( like may have path 1 and path2 for same query),then What CBO does is, it
basically calculates the cost of each path and the analyses for which path the cost
of execution is less and then executes that path so that it can optimize the quey
execution.




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                      Informatica Questions & Answers
2. Rule base optimizer(RBO): this basically follows the rules which are needed for
executing a query. So depending on the number of rules which are to be applied,
the optimzer runs the query.

Use:
If the table you are trying to query is already analysed, then oracle will go with CBO.

If the table is not analysed , the Oracle follows RBO.
For the first time, if table is not analysed, Oracle will go with full table scan.

137) What will happen if you are using Update Strategy Transformation and your
session is configured for "insert"? What are the types of External Loader available
with Informatica? If you have rank index for top 10. However if you pass only 5
records, what will be the output of such a Rank Transformation?

Ans)   if u r using a update strategy in any of ur mapping, then in session properties u have to set
treat source rows as Data Driven. if u select insert or udate or delete, then the info server will not
consider UPD for performing any DB operations.
ELSE
u can use the UPD session level options. instead of using a UPD in mapping just select the
update in treat source rows and update else insert option. this will do the same job as UPD. but
be sure to have a PK in the target table.
2) for oracle : SQL loader
for teradata:tpump,mload.
3) if u pass only 5 rows to rank, it will rank only the 5 records based on the rank port.

138) What is aggregate cache in aggregator transforamtion?
Ans) When you run a workflow that uses an Aggregator transformation, the
Informatica Server creates index and data caches in memory to process the
transformation. If the Informatica Server requires more space, it stores overflow
values in cache files.

139) Which transformation should we use to normalize the COBOL and relational
sources?
Ans) The Normalizer transformation normalizes records from COBOL and relational
sources, allowing you to organize the data according to your own needs. A
Normalizer transformation can appear anywhere in a data flow when you normalize
a relational source. Use a Normalizer transformation instead of the Source Qualifier
transformation when you normalize a COBOL source. When you drag a COBOL
source into the Mapping Designer workspace, the Normalizer transformation
automatically appears, creating input and output ports for every column in the
source

140) What are the measure objects
Ans) Aggregate calculation like sum,avg,max,min these are the measure objetcs.

141) What is DTM process?
Ans) After the loadmanger performs validations for session,it creates the DTM
process.DTM is to create and manage the threads that carry out the session tasks.I
creates the




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                     Informatica Questions & Answers
master thread.Master thread creates and manges all the other threads.DTM means
data transformation manager.in informatica this is main back ground process.it run
after complition of load manager.in this process informatica server search source
and tgt connection in repository if it correct then informatica server fetch the data
from source and load it to target.

142)What are the options in the target session of update strategy transformation?
Ans) Insert
Delete
Update
Update as update
Update as insert
Update esle insert
Truncate table

143) What are the designer tools for creating tranformations?
Ans) Mapping designer
Tansformation developer
Mapplet designer.


144) What is Code Page used for?
Ans) Code Page is used to identify characters that might be in different languages.
If you are importing Japanese data into mapping, you must select the Japanese code
page of source data.

145) Can i start and stop single session in concurent bstch?
Ans) Just right click on the particular session and going to recovery option or by
using event wait and event rise

146) What are the rank caches?
Ans) During the session ,the informatica server compares an inout row with rows in
the datacache.If the input row out-ranks a stored row,the informatica server
replaces the
stored row with the input row.The informatica server stores group information in an
index cache and row data in a data cache.

147) Why and where we are using factless fact table?
Ans) Factless Fact Tables are the fact tables with no facts or measures(numerical
data). It contains only the foriegn keys of corresponding Dimensions. Factless fact is
used to track the events by using the key values

148) How can you delete duplicate rows with out using Dynamic Lookup? Tell me
any other ways using lookup delete the duplicate rows?
Ans) For example u have a table Emp_Name and it has two columns Fname, Lname
in the source table which has douplicate rows. In the mapping Create Aggregator
transformation. Edit the aggregator transformation select Ports tab select Fname
then click the check box on GroupBy and uncheck the (O) out port. select Lname
then uncheck the (O) out port and click the check box on GroupBy. Then create 2
new ports Uncheck the (I) import then click Expression on each port. In the first new




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                   Informatica Questions & Answers
port Expression type Fname. Then second Newport type Lname. Then close the
aggregator transformation link to the target table.

149) What are the different options used to configure the sequential batches?
Ans) Two options
Run the session only if previous session completes sucessfully. Always runs the
session.

150) How to Generate the Metadata Reports in Informatica?
Ans) You can generate PowerCenter Metadata Reporter from a browser on any
workstation, even a workstation that does not have PowerCenter tools installed.

151) How do we estimate the number of partitons that a mapping really requires?
Is it dependent on the machine configuration?
Ans) It depends upon the informatica version we r using. suppose if we r using
informatica 6 it supports only 32 partitions where as informatica 7 supports 64
partitions.

152) How the informatica server sorts the string values in Ranktransformation?
Ans) When the informatica server runs in the ASCII data movement mode it sorts
session data using Binary sortorder.If you configure the seeion to use a binary sort
order,the
informatica server caluculates the binary value of each string and returns the
specified number of rows with the higest binary values for the string.

153) How can U create or import flat file definition in to the warehouse designer?
Ans) U can create flat file definition in warehouse designer.in the warehouse
designer,u can create new target: select the type as flat file. save it and u can enter
various columns for that created target by editing its properties.Once the target is
created, save it. u can import it from the mapping designer.

154) To provide support for Mainframes source data,which files r used as a source
definitions?
Ans) COBOL Copy-book files

155) Can u copy the session to a different folder or repository?
Ans) In addition, you can copy the workflow from the Repository manager. This will
automatically copy the mapping, associated source,targets and session to the
target folder.Yes it is possible. For copying a session to a folder in the same
repository or to another in a different repository, we can use the repository
manager ( which is client sid etool).Simply by just dragging the session to the target
destination, the session will be copied.

156) How to get two targets T1 containing distinct values and T2 containing
duplicate values from one source S1.
Ans) Use filter transformation for loading the target with no duplicates. and for the
other transformation load it directly from source.The above requirement can be achived
using Lookup transformation in Dynamic mode

157) What is worklet and what use of worklet and in which situation we can use it




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                  Informatica Questions & Answers
Ans) A set of worlflow tasks is called worklet,
Workflow tasks means
1)timer2)decesion3)command4)eventwait5)eventrise6)mail etc......

158) We are using Update Strategy Transformation in mapping how can we know
whether insert or update or reject or delete option has been selected during
running of sessions in Informatica.
Ans) In Designer while creating Update Strategy Transformation uncheck "forward
to next transformation". If any rejected rows are there automatically it will be
updated to the session log file.
Update or insert files are known by checking the target file or table only.

159) What are the different types of Type2 dimension maping?
Ans) Type2 Dimension/Version Data Maping: In this maping the updated dimension
in the source will gets inserted in target along with a new version number. Newly
added
dimension in source will inserted into target with a primary key.

Type2 Dimension/Flag current Maping: This maping is also used for slowly changing
dimensions.In addition it creates a flag value for changed or new dimension.

Flag indiactes the dimension is new or newlyupdated.Recent dimensions will gets
saved with cuurent flag value 1. And updated dimensions are saved with the value
0.

Type2 Dimension/Effective Date Range Maping: This is also one flavour of Type2
maping used for slowly changing dimensions.This maping also inserts both new and
changed dimensions in to the target. And changes are tracked by the effective date
range for each version of each dimension.

160) Can you use the maping parameters or variables created in one maping into
any other reusable transformation?
Ans) Yes.Because reusable tranformation is not contained with any maplet or
maping.

161) What is tracing level?
Ans) Ya its the level of information storage in session log.
The option comes in the properties tab of transformations. By default it remains
"Normal". Can be
Verbose Initialisation
Verbose Data
Normal
or Terse.

162) What is meant by EDW?
Ans) EDW is Enterprise Datawarehouse which means that its a centralised DW for
the whole organization.

this apporach is the apporach on Imon which relies on the point of having a single
warehouse/centralised where the kimball apporach says to have seperate data
marts for each vertical/department.




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                   Informatica Questions & Answers

Advantages of having a EDW:

1. Golbal view of the Data

2. Same point of source of data for all the users acroos the organization.

3. able to perform consistent analysis on a single Data Warehouse.

to over come is the time it takes to develop and also the management that is
required to build a centralised database.

163) There are 1000 source tables containing the same data with different file
formats,now i want to load into a single target table ..how to achieve ?
Ans) first u should convert diff. file format to one format then create 1 to 1
mapping,run it and see the o/p in unix whether file is posted or not.

164) Where is the cache stored in informatica?
Ans) Cache is stored in the Informatica server memory and over flowed data is
stored on the disk in file format which will be automatically deleted after the
successful completion of the session run. If you want to store that data you have to
use a persistant cache.

165) Can you start a batches with in a batch?
Ans) You can not. If you want to start batch that resides in a batch,create a new
independent batch and copy the necessary sessions into the new batch.

166) What is a command that used to run a batch?
Ans) pmcmd is used to start a batch.

167) What are the unsupported repository objects for a mapplet?
Ans) COBOL source definition
Joiner transformations
Normalizer transformations
Non reusable sequence generator transformations.
Pre or post session stored procedures
Target defintions
Power mart 3.5 style Look Up functions
XML source definitions
IBM MQ source defintions.

168) What r the types of metadata that stores in repository?
Ans) Source definitions. Definitions of database objects (tables, views, synonyms) or
files that provide source data.
Target definitions. Definitions of database objects or files that contain the target
data.
Multi-dimensional metadata. Target definitions that are configured as cubes and
dimensions.
Mappings. A set of source and target definitions along with transformations
containing business logic that you build into the transformation. These are the
instructions that the Informatica Server uses to transform and move data.




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                    Informatica Questions & Answers
Reusable transformations. Transformations that you can use in multiple mappings.
Mapplets. A set of transformations that you can use in multiple mappings.
Sessions and workflows. Sessions and workflows store information about how and
when the Informatica Server moves data. A workflow is a set of instructions that
describes how and when to run tasks related to extracting, transforming, and
loading data. A session is a type of task that you can put in a workflow. Each
session corresponds to a single mapping.

169) How do we analyse the data at database level?
Ans) Data can be viewed using Informatica's designer tool.
If you want to view the data on source/target we can preview the data but with
some limitations.
We can use data profiling too.

170) In my source table 1000 rec's r there.I want to load 501 rec to 1000 rec into
my Target table ? how can u do this ?

Ans)   You can overide the sql Query in Wofkflow Manager. LIke
select * from tab_name where rownum<=1000
minus

select * from tab_name where rownum<=500;
This will work fine. Try it and get back to me if u have any issues about the same.Use the below
query:
select * from (select rownum r, from test_table) where r between 3 and 6
will fetch rows between a range.

171) Can any one explain real time complain mappings or complex
transformations in Informatica. Specially in Sales Domain.
Ans) Most complex logic we use is denormalization. We dont have any Denormalizer
transformation in INformatica. So we will have to use an aggregator followed by an
expression. Apart from this, we use most of the complexicity in expression
transformation involving lot of nested IIF's and Decode statements...another one is
the union tranformation and joiner.

172) Could anyone please tell me what are the steps required for type2
dimension/version data mapping. how can we implement it
Ans) 1. Determine if the incoming row is 1) a new record 2) an updated record or 3)
a record that already exists in the table using two lookup transformations. Split the
mapping into 3 seperate flows using a router transformation.
2. If 1) create a pipe that inserts all the rows into the table.
3. If 2) create two pipes from the same source, one updating the old record, one to
insert the new.

173) If you are workflow is running slow in informatica. Where do you start
trouble shooting and what are the steps you follow?
Ans) When the work flow is running slowly u have to find out the bottlenecks
in this order
target
source




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                     Informatica Questions & Answers
mapping
session
system

174) Identifying bottlenecks in various components of Informatica and resolving
them.
Ans) The best way to find out bottlenecks is writing to flat file and see where the
bottle neck is .

175) Can we lookup a table from a source qualifer transformation-unconnected
lookup
Ans) No. we can't do.

I will explain you why.

1) Unless you assign the output of the source qualifier to another transformation or
to target no way it will include the feild in the query.

2) source qualifier don't have any variables feilds to utalize as expression.

176) What r the tasks that Loadmanger process will do?
Ans) Manages the session and batch scheduling: Whe u start the informatica server
the load maneger launches and queries the repository for a list of sessions
configured to run on the informatica server.When u configure the session the
loadmanager maintains list of list of sessions and session start times.When u sart a
session loadmanger fetches the session information from the repository to perform
the validations and verifications prior to starting DTM process.
Locking and reading the session: When the informatica server starts a session
lodamaager locks the session from the repository.Locking prevents U starting the
session again and again.
Reading the parameter file: If the session uses a parameter files,loadmanager reads
the parameter file and verifies that the session level parematers are declared in the
file
Verifies permission and privelleges: When the sesson starts load manger checks
whether or not the user have privelleges to run the session.
Creating log files: Loadmanger creates logfile contains the status of session. The LM
also sends the 'failure mails' in case of failure in execution of the Subsequent DTM process.

177) How can you stop a batch?
Ans) By using server manager or pmcmd.

178) What is metadata reporter?
Ans) It is a web based application that enables you to run reports againist
repository metadata.
With a meta data reporter,You can access information about U?r repository with out
having knowledge of sql,transformation language or underlying tables in the
repository.

179) Suppose session is configured with commit interval of 10,000 rows and
source has 50,000 rows. Explain the commit points for Source based commit and
Target based commit. Assume appropriate value wherever required.




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                    Informatica Questions & Answers
Ans) Source based commit will commit the data into target based on commit
interval.so,for every 10,000 rows it will commit into target.
Target based commit will commit the data into target based on buffer size of the
target.i.e., it commits the data into target when ever the buffer fills.Let us assume
that the buffer size is 6,000.So,for every 6,000 rows it commits the data.

180) What is the default source option for update stratgey transformation?
Ans) Data driven.

181) Difference between summary filter and details filter?
Ans) Summary Filter --- we can apply records group by that contain common
values.
Detail Filter --- we can apply to each and every record in a database.

182) What are the reusable transforamtions?
Ans) Reusable transformations can be used in multiple mappings.When you need to
incorporate this transformation into maping,U add an instance of it to maping.Later
if you change the definition of the transformation ,all instances of it inherit the
changes.Since the instance of reusable transforamation is a pointer to that
transforamtion,You can change the transforamation in the transformation
developer,its instances automatically reflect these changes.This feature can save
you great deal of work.A reusable Transformation is a reusable metadata object , defined with
business logic using single Transformation.

183) What r the types of maping wizards that r to be provided in Informatica?
Ans) Simple Pass through
Slowly Growing Target

Slowly Changing the Dimension
Type1
Most recent values
Type2
Full History
Version
Flag
Date
Type3
Current and one previous

184) After draging the ports of three sources(sql server,oracle,informix) to a
single source qualifier, can u map these three ports directly to target?
Ans) if u drag three hetrogenous sources and populated to target without any join
means you are entertaining Carteisn product. If you don't use join means not only
diffrent sources but homegeous sources are show same error.
If you are not interested to use joins at source qualifier level u can add some joins
sepratly. In Source qualifier we can join the tables from same database only.

185) What is difference between partioning of relatonal target and partitioning of
file targets?




                                              35
                   Informatica Questions & Answers
Ans) If u parttion a session with a relational target informatica server creates
multiple connections to the target database to write target data concurently.If u
partition a session with a file target the informatica server creates one target file for
each partition.You can configure session properties to merge these target files.

186) What is aggregate cache in aggregator transforamtion?
Ans) The aggregator stores data in the aggregate cache until it completes
aggregate calculations.When you run a session that uses an aggregator
transformation,the informatica server creates index and data caches in memory to
process the transformation.If the informatica server requires more space,it stores
overflow values in cache files.

187) What are the properties should be notified when we connect the flat file
source definition to relational database target definition?
Ans) 1.File is fixed width or delimited
2.Size of the file.
If its can be executed without performance issues then normal load will work
If its huge in GB they NWAY partitions can be specified at the source side and the
target side.
3.File reader,source file name etc .....

187) Why we use stored procedure transformation?
Ans) A Stored Procedure transformation is an important tool for populating and
maintaining databases. Database administrators create stored procedures to
automate time-consuming tasks that are too complicated for standard SQL
statements.

188) Which objects are required by the debugger to create a valid debug session?
Ans) Intially the session should be valid session.

source, target, lookups, expressions should be availble, min 1 break point should be
available for debugger to debug your session.

189) How do you decide whether you need ti do aggregations at database level or
at Informatica level?
Ans) It depends upon our requirment only.If you have good processing database
you can create aggregation table or view at database level else its better to use
informatica. Here i'm explaing why we need to use informatica.
what ever it may be informatica is a thrid party tool, so it will take more time to
process aggregation compared to the database, but in Informatica an option we
called "Incremental aggregation" which will help you to update the current values
with current values +new values. No necessary to process entire values again and
again. Unless this can be done if nobody deleted that cache files. If that happend
total aggregation we need to execute on informatica also.
In database we don't have Incremental aggregation facility.

190) How is the union transformation active transformation?
Ans) Active Transformation: the transformation that change the no. of rows in the
Target.
Source (100 rows) ---> Active Transformation ---> Target (< or > 100 rows)
Passive Transformation: the transformation that does not change the no. of rows in




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                     Informatica Questions & Answers
the Target.
Source (100 rows) ---> Passive Transformation ---> Target (100 rows)
Union Transformation:Here Union Transformation acts like a UnionAll in SQl.i.e.,it wil
also include duplicates while concatinating two tables.bt,we were provided with a
option to eliminate duplicates also..dats y it's become as an active transformation

191) How to get the first 100 rows from the flat file into the target?
Ans) 1. Use test download option if you want to use it for testing.
2. Put counter/sequence generator in mapping and perform it. Its simple.take a filter
drag all ports from source qualifier to filter. in filter write the condition columname<101 and
drag ports to the target

192) What is meant by complex mapping
Ans) Complex maping means involved in more logic and more business rules.
Actually in my project complex mapping is
In my bank project, I involved in construct a 1 dataware house
Meny customer is there in my bank project, They r after taking loans relocated in to
another place
that time i feel to diffcult maintain both prvious and current adresses
in the sense i am using scd2
This is an simple example of complex mapping

193) Can you start a session inside a batch idividually?
Ans) We can start our required session only in case of sequential batch.in case of
concurrent batch we cant do like this.

194) Can we use aggregator/active transformation after update strategy
transformation
Ans) You can use aggregator after update strategy. The problem will be, once you
perform the update strategy, say you had flagged some rows to be deleted and you
had performed aggregator transformation for all rows, say you are using SUM
function, then the deleted rows will be subtracted from this aggregator
transformation.


195) Can you copy the batches?
Ans) NO.

196) Explain the informatica Architecture in detail
Ans) informatica server connects source data and target data using native
odbc drivers
again it connect to the repository for running sessions and retriveing metadata
information
source------>informatica server--------->target

REPOSITORY
The PowerCenter Server is a repository client application. It connects to the
Repository Server and Repository Agent to retrieve workflow and mapping
metadata from the repository database. When the PowerCenter Server requests a
repository connection from the Repository Server, the Repository Server starts and




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                  Informatica Questions & Answers
manages the Repository Agent. The Repository Server then re-directs the
PowerCenter Server to connect directly to the Repository Agent.

197) What is Load Manager?
Ans) The load Manager is the Primary Informatica Server Process. It performs the
following tasks:-
Manages session and batch scheduling.
Locks the session and read session properties.
Reads the parameter file.
Expand the server and session variables and parameters.
Verify permissions and privileges.
Validate source and target code pages.
Create the session log file.
Create the Data Transformation Manager which execute the session.

198) In which circumstances that informatica server creates Reject files?
Ans) When it encounters the DD_Reject in update strategy transformation.
Violates database constraint
Filed in the rows was truncated or overflowed.

199) Describe two levels in which update strategy transformation sets?
Ans) Within a session: When you configure a session, yoYou can instruct the
Informatica Server to either treat all records in the same way (for example, treat all
records as inserts), or use instructions coded into the session mapping to flag
records for different database operations.

Within a mapping: Within a mapping, you use the Update Strategy transformation to
flag records for insert, delete, update, or reject.

200) Can U use the maping parameters or variables created in one maping into
another maping?
Ans) NO. You might want to use a workflow parameter/variable if you want it to be
visible with other mappings/sessions

201) What is Partitioning ? where we can use Partition? wht is advantages?Is it
nessisary?
Ans) Partitions are used to optimize the session performance
we can select in sesstion propetys for partiotions
types
default----passthrough partition
key range partion
round robin partion
hash partiotion

202) In realtime which one is better star schema or snowflake star schema the
surrogate will be linked to which columns in the dimension table.
Ans) In real time only star schema will implement because it will take less time and
surrogate key will there in each and every dimension table in star schema and this
surrogate key will assign as foreign key in fact table.

203) What is the exact meaning of domain?




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                     Informatica Questions & Answers
Ans) Domain is nothing but give a comlete information on a particular subject area..
like sales domain,telecom domain..etc,. The PowerCenter domain is the fundamental
administrative unit in PowerCenter. The domain supports the administration of the distributed
services. A domain is a collection of nodes and services that you can group in folders based on
administration ownership.

204) How can u work with remote database in informatica?did u work directly by
using remote connections?
Ans) You can work with remote,
But you have to
Configure FTP
Connection details
IP address
User authentication

205) What is lookup transformation and update strategy transformation and
explain with an example.
Ans) Look up transformation is used to lookup the data in a relationa
table,view,Synonym and Flat file.
The informatica server queries the lookup table based on the lookup ports used in
the transformation.
It compares the lookup transformation port values to lookup table column values
based on the lookup condition
By using lookup we can get the realated value,Perform a caluclation and Update
SCD.
Two types of lookups
Connected
Unconnected
Update strategy transformation
This is used to control how the rows are flagged for insert,update ,delete or reject.
To define a flagging of rows in a session it can be insert,Delete,Update or Data
driven.
In Update we have three options
Update as Update
Update as insert
Update else insert

206) What is batch and describe about types of batches?
Ans) Grouping of session is known as batch. Batches are two types:-
Sequential: Runs sessions one after the other
Concurrent: Runs session at same time.
If you have sessions with source-target dependencies you have to go for sequential
batch to start the sessions one after another.If you have several independent
sessions You can use concurrent batches which runs all the sessions at the same
time.

207) What is meant by lookup caches?
Ans) The informatica server builds a cache in memory when it processes the first
row af a data in a cached look up transformation.It allocates memory for the cache
based on the




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                  Informatica Questions & Answers
amount you configure in the transformation or session properties.The informatica
server stores condition values in the index cache and output values in the data
cache.

208) How many ways you can update a relational source defintion and what are
they?
Ans) Two ways:-
1. Edit the definition
2. Reimport the defintion.

209) What is exact use of 'Online' and 'Offline' server connect Options while
defining Work flow in Work flow monitor? . The system hangs when 'Online' server
connect option. The Informatica is installed on a Personal laptop.
Ans) When the repo is up and the PMSERVER is also up, workflow monitor always
will be connected on-line.
When PMserver is down and the repo is still up we will be prompted for an off-line
connection with which we can just monitor the workflows

210) Which is better among connected lookup and unconnected lookup
transformations in informatica or any other ETL tool?
Ans) If you are having defined source you can use connected, source is not well
defined or from different database you can go for unconnected

211) Why you use repository connectivity?
Ans) When you edit,schedule the sesion each time,informatica server directly
communicates the repository to check whether or not the session and users are
valid.All the metadata of sessions and mappings will be stored in repository.

212) What is Session and Batches?
Ans) Session - A Session Is A set of instructions that tells the Informatica Server
How And When To Move Data From Sources To Targets. After creating the session,
we can use
either the server manager or the command line program pmcmd to start or stop the
session.
Batches - It Provides A Way to Group Sessions For Either Serial Or Parallel
Execution By The Informatica Server.
There Are Two Types Of Batches :
Sequential - Run Session One after the Other.
Concurrent - Run Session At The Same Time.

213) Can u generate reports in Informatcia?
Ans) It is a ETL tool, you could not make reports from here, but you can generate
metadata report, that is not going to be used for business analysis

214) How to recover the standalone session?
Ans) A standalone session is a session that is not nested in a batch. If a standalone
session fails, you can run recovery using a menu command or pmcmd. These
options are
not available for batched sessions.
To recover sessions using the menu:
1. In the Server Manager, highlight the session you want to recover.




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                   Informatica Questions & Answers
2. Select Server Requests-Stop from the menu.
3. With the failed session highlighted, select Server Requests-Start Session in
Recovery Mode from the menu.
To recover sessions using pmcmd:
1.From the command line, stop the session.
2. From the command line, start recovery.

215) How do you create a mapping using multiple lookup transformation?
Ans) Use unconnected lookup if same lookup repeats multiple times.

216) What is the procedure to write the query to list the highest salary of three
employees?
Ans) The following is the query to find out the top three salaries
in ORACLE:--(take emp table)
select * from emp e where 3>(select count (*) from emp where
e.sal>emp.sal) order by sal desc.
in SQL Server:-(take emp table)
select top 10 sal from emp
[ORACLE] - select * from (SELECT emp_name,salary from bbc order by area salary desc)
where rownum<=3

217) Is a fact table normalized or de-normalized?
Ans) A fact table is always DENORMALISED table. It consists of data from dimension
table (Primary Key's) and Fact table has Foreign keys and measures.

218) What is the mapping for unit testing in Informatica, are there any other
testings in Informatica, and how we will do them as a etl developer. how do the
testing people will do testing are there any specific tools for testing
Ans) In informatica there is no method for unit testing. There are two methods to
test the mapping.
1. But we have data sampling. set the ata sampling properties for session in
workflow manager for specified number of rows and test the mapping.
2. Use the debugger and test the mapping for sample records.

219) Can batches be copied/stopped from server manager?
Ans) Yes, we can stop the batches using server manager or pmcmd commnad

220) Can i use a session Bulk loading option that time can i make a recovery to the
session?
Ans) If the session is configured to use in bulk mode it will not write recovery
information to recovery tables. So Bulk loading will not perform the recovery as
required.

221) Can we add different work flows in to one batch and run sequentially? If pos
how do we do that?
Ans) For simulating a batch we can create a unix script and write pmcmd
commands for running different workflows one after other into that unix script . like
workflowrun.sh(Giving example for informatica 8 )
pmcmd startworkflow -sv IS_INTEGRATION_SERVICE -d DOMAIN1 -u myuser -p
mypass -f folder1 workflow1
pmcmd startworkflow -sv IS_INTEGRATION_SERVICE -d DOMAIN1 -u myuser -p




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                     Informatica Questions & Answers
mypass -f folder1 workflow2
Save this file and run the same .
This will trigger workflow1 and then workflow2.

222) How to retrive the records from a rejected file. explane with syntax or
example
Ans) During the execution of workflow all the rejected rows will be stored in bad
files(where your informatica server get installed;C:Program FilesInformatica
PowerCenter 7.1Server) These bad files can be imported as flat a file in source then
thro' direct maping we can load these files in desired format.

223) If the workflow has 5 session and running sequentially and 3rd session
hasbeen failed how can we run again from only 3rd to 5th session?
Ans) If multiple sessions in a concurrent batch fail, you might want to truncate all
targets and run the batch again. However, if a session in a concurrent batch fails
and the rest of the sessions complete successfully, you can recover the session as a
standalone session.To recover a session in a concurrent batch:1.Copy the failed
session using Operations-Copy Session.2.Drag the copied session outside the batch
to be a standalone session.3.Follow the steps to recover a standalone
session.4.Delete the standalone copy.Hi, as per the questions all the sessions are serial. So
you can start the session as "start workflow from task" from there it wil continue to run the rest
of the tasks.

224) How i can do incremental aggregation in real time?
Ans) For incremental Aggregation.. We need to use Aggregations + Look up on
Target + Expression to SUM up Count obtained from New Aggregations and Lookup
on target.
For one record already present in Aggregations table.. count is also there..
It will be available in lookup.. new count will be available through AGG.. Sum then
up and update that record in target..

225) If i done any modifications for my table in back end does it reflect in
informatca warehouse or maping desginer or source analyzer?
Ans) NO. Informatica is not at all concern with back end data base.It displays u all
the information that is to be stored in repository.If want to reflect back end changes
to informatica screens, again u have to import from back end to informatica by valid
connection.And u have to replace the existing files with imported files.

226) How the informatica server increases the session performance through
partitioning the source?
Ans) For a relational sources informatica server creates multiple connections for
each parttion of a single source and extracts seperate range of data for each
connection.Informatica server reads multiple partitions of a single source
concurently.Similarly for loading also informatica server creates multiple
connections to the target and loads partitions of data concurently.

For XML and file sources,informatica server reads multiple files concurently.For
loading the data informatica server creates a seperate file for each partition(of a
source file).U can choose to merge the targets.

227) How to join two tables without using the Joiner Transformation.




                                                35
                     Informatica Questions & Answers
Ans) Itz possible to join the two or more tables by using source qualifier.But
provided the tables should have relationship.
When u drag n drop the tables u will getting the source qualifier for each
table.Delete all the source qualifiers.Add a common source qualifier for all.Right
click on the source qualifier u will find EDIT click on it.Click on the properties tab,u
will find sql query in that u can write ur sqls. You can also do it using
Session --- mapping---source--- there you have an option called User Defined Join there you can
write your SQL

228) When we create a target as flat file and source as oracle.. how can i specify
first rows as column names in flat files...
Ans) Use a pre sql statement....but this is a hardcoding method...if you change the
column names or put in extra columns in the flat file, you will have to change the
insert statement

229) What happens if you try to create a shortcut to a non-shared folder?
Ans) It only creates a copy of it..

230) Explain about Recovering sessions?
Ans) If you stop a session or if an error causes a session to stop, refer to the session
and error logs to determine the cause of failure. Correct the errors, and then
complete the
session. The method you use to complete the session depends on the properties of
the mapping, session, and Informatica Server configuration.
Use one of the following methods to complete the session:
? Run the session again if the Informatica Server has not issued a commit.
? Truncate the target tables and run the session again if the session is not
recoverable.
? Consider performing recovery if the Informatica Server has issued at least one
commit.

231) Can Informatica load heterogeneous targets from heterogeneous sources?
Ans) Yes it can. For example...Flat File and Relations sources are joined in the
mapping, and later, Flat File and relational targets are loaded.

232) While running multiple session in parallel which loads data in the same table,
throughput of each session becomes very less and almost same for each session.
How can we improve the performance (throughput) in such cases?
Ans) I think this will be handled by the database we use.
When the operations/loading on the table is in progress the table will be locked.
If we are trying to load the same table with different partitions then we run into
rowID erros if the database is 9i and we can apply a patch to reslove this issue

233) What is data merging, data cleansing, sampling?
Ans) Cleansing:---TO identify and remove the retundacy and inconsistency
sampling: just smaple the data throug send the data from source to target

Data merging: It is a process of combining the data with similar structures in to a single output.
Data Cleansing: It is a process of identifying and rectifying the inconsistent and inaccurate data




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                    Informatica Questions & Answers

into consistent and accurate data
Data Sampling:It is the process of sample by sending the data from source to target

234) What is Code Page Compatibility?
Ans) Compatibility between code pages is used for accurate data movement when
the Informatica Sever runs in the Unicode data movement mode. If the code pages
are
identical, then there will not be any data loss. One code page can be a subset or
superset of another. For accurate data movement, the target code page must be a
superset of the source code page.
Superset - A code page is a superset of another code page when it contains the
character encoded in the other code page, it also contains additional characters not
contained in the other code page.
Subset - A code page is a subset of another code page when all characters in the
code page are encoded in the other code page.

235) There are 3 depts in dept table and one with 100 people and 2nd with 5 and
3rd with some 30 and so. i want to diplay those deptno where more than 10
people exists
Ans) If you want to perform it thru informatica, the Fire the same query in the SQL
Override of Source qualifier transformation and make a simple pass thru mapping.
Other wise, you can also do it by using a Filter.Router transformation by giving the
condition there deptno>=10.

236) How to load the data from people soft hrm to people soft erm using
informatica?
Ans) Following are necessary
1.Power Connect license
2.Import the source and target from people soft using ODBC connections
3.Define connection under "Application Connection Browser" for the people soft
source/target in workflow manager .
select the proper connection (people soft with oracle,sybase,db2 and informix)
and execute like a normal session.

237) Somebody ca explain me the 3 points:I want to Know : 1) the differences
between using native and ODBC server-side databaseConnections 2)Know the
reason why to register a server to the repository is necessary 3)Know the rules
associated with transferring and sharing objects between folders. 4) Know the
rules associated with transferring and sharing objects between repositories
Ans) 1> Native connection is something which is provided by the same vendor for
that tool. eg: oracle warehouse builder has its own driver to connect to oracle DB
which does not use a ODBC driver. here connection will be fast and hence
performance.
ODBC is basically a third party driver like Microsoft driver for Oracle, which can be
used by any tool to connect to oracle.
2> Registering a server to a repository is necessary because the sessions will be
using this server to run. If we have multiple servers, then we can use diff server to
diff sessions to run.
238) I have an requirement where in the columns names in a table (Table A)
should appear in rows of target table (Table B) i.e. converting columns to rows. Is
it possible through Informatica? If so, how?




                                               35
                   Informatica Questions & Answers
Ans) if data in tables as follows
Table A
Key-1 char(3);
table A values
_______
1
2
3

Table B
bkey-a char(3);
bcode char(1);
table b values
1T
1A
1G
2A
2T
2L
3A

and output required is as

1, T, A
2, A, T, L
3, A

the SQL query in source qualifier should be

select key_1,
max(decode( bcode, 'T', bcode, null )) t_code,
max(decode( bcode, 'A', bcode, null )) a_code,
max(decode( bcode, 'L', bcode, null )) l_code
from a, b
where a.key_1 = b.bkey_a
group by key_1
/

239) Explain about perform recovery?
Ans) When the Informatica Server starts a recovery session, it reads the
OPB_SRVR_RECOVERY table and notes the row ID of the last row committed to the
target database.
The Informatica Server then reads all sources again and starts processing from the
next row ID. For example, if the Informatica Server commits 10,000 rows before the
session fails, when you run recovery, the Informatica Server bypasses the rows up
to 10,000 and starts loading with row 10,001.By default, Perform Recovery is
disabled in the Informatica Server setup. You must enable Recovery in the
Informatica Server setup before you run a session so the
Informatica Server can create and/or write entries in the OPB_SRVR_RECOVERY
table.




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                   Informatica Questions & Answers

240) Can any one tell me how to run scd1 bec it create two target tables in
mapping window and there are only one table in warehouse designer(means
target).. so if we create one new table in target it gives error..
Ans) If so, create the target with the name u have given in wizard for target(table).
No't create the target again for the second instance. It is just the virtual copy of the
same target. i.e in warehouse designer create and execute the target definitions
and run the session containing the mapping again.define the source& target
locations in general properties of sessiontreat rows as: Data DrivenCheck this once
and let me know

241) i have source like 1;2:3.4 its flatfile. now i want in my target table as 1 2 3 4
plz can any one explain me the procedure how to get output like dat
Ans) No answer available currently. Be the first one to reply to this question by
submitting your answer from the form below.

242) In a sequential batch can you run the session if previous session fails?
Ans) Yes.By setting the option always runs the session.

243) In a filter expression we want to compare one date field with a db2 system
field CURRENT DATE. Our Syntax: datefield = CURRENT DATE (we didn't define it
by ports, its a system field ), but this is not valid (PMParser: Missing Operator)..
Ans) The db2 date formate is "yyyymmdd" where as sysdate in oracle will give "dd-
mm-yy" so conversion of db2 date formate to local database date formate is
compulsary. other wise u will get that type of error

244) How do you transfert the data from data warehouse to flatfile?
Ans) You can write a mapping with the flat file as a target using a
DUMMY_CONNECTION. A flat file target is built by pulling a source into target space
using Warehouse Designer tool.

245) What is the Rank index in Rank transformation?
Ans) Based on which port you want generate Rank is known as rank port, the
generated values are known as rank index.

246) Define Informatica Repository?
Ans) The Informatica repository is a relational database that stores information, or
metadata, used by the Informatica Server and Client tools. Metadata can include
information
such as mappings describing how to transform source data, sessions indicating
when you want the Informatica Server to perform the transformations, and connect
strings
for sources and targets.
The repository also stores administrative information such as usernames and
passwords, permissions and privileges, and product version.
Use repository manager to create the repository.The Repository Manager connects
to the repository database and runs the code needed to create the repository
tables.Thsea tables
stores metadata in specific format the informatica server,client tools use.

247) What is change data capture?




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                    Informatica Questions & Answers
Ans) Change data capture (CDC) is a set of software design patterns used to
determine the data that has changed in a database so that action can be taken
using the changed data.

248) Can any body write a session parameter file which will change the source
and targets for every session. i.e different source and targets for each session run.
Ans) You are supposed to define a parameter file. And then in the Parameter file,
you can define two parameters, one for source and one for target.
Give like this for example:
$Src_file = c:program filesinformaticaserverinabc_source.txt
$tgt_file = c: argetsabc_targets.txt
Then go and define the parameter file:
[folder_name.WF:workflow_name.ST:s_session_name]
$Src_file =c:program filesinformaticaserverinabc_source.txt
$tgt_file = c: argetsabc_targets.txt
If its a relational db, you can even give an overridden sql at the session level...as a
parameter. Make sure the sql is in a single line.

249) What is meant by Junk Attribute in Informatica?
Ans) Junk Dimension A Dimension is called junk dimension if it contains attribute
which are rarely changed ormodified. example In Banking Domain , we can fetch
four attributes accounting to a junk dimensions like from the
Overall_Transaction_master table tput flag tcmp flag del flag advance flag all these
attributes can be a part of a junk dimensions.Grouping of random flags and text attributes
in a dimension and moving them to a separate dimension is called as junk dimension

250) What are partition points?
Ans) Partition points mark the thread boundaries in a source pipeline and divide
the pipeline into stages.Partition points mark the thread boundaries in a pipeline
and
divide the pipeline into stages. The Informatica Server sets partition points at
several
transformations in a pipeline by default. If you use PowerCenter, you can define
other partition
points. When you add partition points, you increase the number of transformation
threads,
which can improve session performance. The Informatica Server can redistribute
rows of data at partition points, which can also improve session performance.

251) Where should U place the flat file to import the flat file defintion to the
designer?
Ans) There is no such restrication to place the source file. In performance point of
view its better to place the file in server local src folder. if you need path please
check the server properties availble at workflow manager.
It doesn't mean we should not place in any other folder, if we place in server src
folder by default src will be selected at time session creation.

252) I have flatfile it contains 'n' number of records. i need to load half of the
records to one target table another half to another target table. plz any one can
explain me the procedure.




                                             35
                  Informatica Questions & Answers
Ans) There will be 2 pipelines
In first pipeline , read from source file , put an expression,in expression take a
variable and increment it by 1 ( v=v+1),then put a target T0,generates sequence in
T0 column.
Now after first pipeline gets executed we have
a) count of all the rows from the file
b) rank of all the records in T0 table and c1 column.
In second pipeline,take T0 as source and T1,T2 as target and router R1 as
transformation in between.
In R1 , put 2 groups ->
1st group c1<=v/2 - direct to T1
2nd group c2>v/2 - direct to T2

253) How can u recover the session in sequential batches?
Ans) If you configure a session in a sequential batch to stop on failure, you can run
recovery starting with the failed session. The Informatica Server completes the
session and
then runs the rest of the batch. Use the Perform Recovery session property
To recover sessions in sequential batches configured to stop on failure:
1.In the Server Manager, open the session property sheet.
2.On the Log Files tab, select Perform Recovery, and click OK.
3.Run the session.
4.After the batch completes, open the session property sheet.
5.Clear Perform Recovery, and click OK.
If you do not clear Perform Recovery, the next time you run the session, the
Informatica Server attempts to recover the previous session.
If you do not configure a session in a sequential batch to stop on failure, and the
remaining sessions in the batch complete, recover the failed session as a
standalone
session.

254) How to use mapping parameters and what is their use
Ans) In designer u will find the mapping parameters and variables options.u can
assign a value to them in designer. comming to there uses suppose u r doing
incremental extractions daily. suppose ur source system contains the day column.
so every day u have to go to that mapping and change the day so that the
particular data will be extracted . if we do that it will be like a layman's work. there
comes the concept of mapping parameters and variables. once if u assign a value to
a mapping variable then it will change between sessions.

255) Diff between informatica repositry server & informatica server
Ans) Informatica Repository Server:It's manages connections to the repository from
client application.
Informatica Server:It's extracts the source data,performs the data
transformation,and loads the transformed data into the target

256) What r the mapping paramaters and maping variables?
Ans) Please refer to the documentation for more understanding.
Mapping variables have two identities:
Start value and Current value




                                          35
                    Informatica Questions & Answers
Start value = Current value ( when the session starts the execution of the undelying
mapping)
Start value <> Current value ( while the session is in progress and the variable
value changes in one ore more occasions)
Current value at the end of the session is nothing but the start value for the
subsequent run of the same session.

257) In certain mapping there are four targets tg1,tg2,tg3 and tg4. tg1 has a
primary key,tg2 foreign key referencing the tg1's primary key,tg3 has primary key
that tg2 and tg4 refers as foreign key,tg2 has foreign key referencing primary key
of tg4 ,the order in which the informatica will load the target? 2]How can I detect
aggregate tranformation causing low performance?
Ans) To optimize the aggregator transformation, you can use the following options.
Use incremental aggregation
Sort the ports before you perform aggregation
Avoid using aggregator transformation after update strategy, since it might be
confusing.
Answer for the second query:
To get performance details for any aggregator transformation, we have to check some parameters
in the .perf file named as Transformationname_writetodisk and
Transformationname_readfromdisk. If these two counters provide values which are not zero then
we have to tune the aggregator transformation. The ways in which the aggregator transformation
can be tuned:
1. Using incremental aggregation
2. By increasing the DATA cache and index cache sizes
3. Using a sorter transformation before the aggregator transformation

258) How many number of sessions that You can create in a batch?
Ans) Any number of sessions.It depends on the config settings of informatica       server. The
parameters for the maximum connections cant be exceeded. It depends on the overall sessions
running per the server at a time. For eg, if the number of connxns rt now is 300 and if u have
batches running with 290+ sessions at a time, adding 15 more sessions to the time frame will
cause the loads to fail

259) Compare Data Warehousing Top-Down approach with Bottom-up approach
Ans) Top down
ODS-->ETL-->Datawarehouse-->Datamart-->OLAP
Bottom up
ODS-->ETL-->Datamart-->Datawarehouse-->OLAP

260) What r the methods for creating reusable transforamtions?
Ans) You can design using 2 methods

using transformation developer
create normal one and promote it to reusable

261) How to export mappings to the production environment?
Ans) In the designer go to the main menu and one can see the export/import
options.
Import the exported mapping in to the production repository with replace




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                     Informatica Questions & Answers

options.You will have to export as xml format using export option and then import in
production environment.

262) where do we use MQ series source qualifier, application multi group source
qualifier. just give an example for a better understanding
Ans) We can use a MQSeries SQ when we have a MQ messaging system as
source(queue).
When there is need to extract data from a Queue, which will basically have
messages in XML format, we will use a JMS or a MQ SQ depending on the messaging
system. If you have a TIBCO EMS Queue, use a JMS source and JMS SQ and an XML
Parser, or if you have a MQ series queue, then use a MQ SQ which will be associated
with a Flat file or a Cobal file.
263) How do we estimate the depth of the session scheduling queue? Where do
we set the number of maximum concurrent sessions that Informatica can run at a
given time?
Ans) u set the max no of concurrent sessions in the info server.by default its 10. u
can set to any no.

264) Discuss which is better among incremental load, Normal Load and Bulk load
Ans) It depends on the requirement. Otherwise Incremental load which can be
better as it takes onle that data which is not available previously on the target.
According to performence bulk is better than normal.
But bolh having some conditions in source data
Conditions are like
1)does not containn any constraint in data.
2)dont use the double datatype if neccesory to use then use it as last row of the table.
3)it does not support the CHECK CONSTRAINT.

265) what is the best way to show metadata(number of rows at source, target and
each transformation level, error related data) in a report format
Ans) You can select these details from the repository table. you can use the view
REP_SESS_LOG to get these data

266) When the informatica server marks that a batch is failed?
Ans) If one of session is configured to "run if previous completes" and that previous
session fails.

267) Which tool you use to create and manage sessions and batches and to
monitor and stop the informatica server?
Ans) Informatica Server Manager.Its the Integration Service in 8.x

268) What is the hierarchies in DWH
Ans) Data sources ---> Data acquisition ---> Warehouse ---> Front end tools --->
Metadata management ---> Data warehouse operation management

269) How can we store previous session logs
Ans) Just run the session in time stamp mode then automatically session log will not
overwrite current session log.




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270) my source is having 1000 rows. i have brought 300 records into my ODS. so
next time i want to load the remaining records. so i need to load from 301 th
record. when ever i start the work flow again it will load from the begining. how
do we solve this problem.
Ans) By using Sequence GeneratorTransformation u can do it
ie by chaging the RESET option in the properties tab of your
SequenceGeneratorTransformation.
then it will workwe can also use recover task so that ,when data is extracting
because of any problem while loading data if it's stop's loading at middle using
recover task we can get the records from where it's stoped previously.....

271) What is Dimension table Exactly?
Ans) Dimension tables gives description about something.
for eg. If we take Student as a dimention table, we have various attributes like
college name, age, gender,etc which gives some description about a student.

272) What are the different threads in DTM process?
Ans) Master thread: Creates and manages all other threads
Maping thread: One maping thread will be creates for each session.Fectchs session
and maping information.
Pre and post session threads: This will be created to perform pre and post session
operations.
Reader thread: One thread will be created for each partition of a source.It reads
data from source.
Writer thread: It will be created to load data to the target.
Transformation thread: It will be created to tranform data.

273) What is a junk dimension
Ans) A "junk" dimension is a collection of random transactional codes, flags and/or
text attributes that are unrelated to any particular dimension. The junk dimension is
simply a structure that provides a convenient place to store the junk attributes. A
good example would be a trade fact in a company that brokers equity trades.

274) What r the circumstances that infromatica server results an unreciverable
session?
Ans) The source qualifier transformation does not use sorted ports.
If u change the partition information after the initial session fails.
Perform recovery is disabled in the informatica server configuration.
If the sources or targets changes after initial session fails.
If the maping consists of sequence generator or normalizer transformation.
If a concuurent batche contains multiple failed sessions.

275) How does the server recognise the source and target databases?
Ans) By using ODBC connection.if it is relational.if is flat file FTP connection..see we
can make sure with connection in the properties of session both sources && targets.

276) Whats the diff between Informatica powercenter server, repositoryserver
and repository?
Ans) By using ODBC connection.if it is relational.if is flat file FTP connection..see we
can make sure with connection in the properties of session both sources && targets.




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                     Informatica Questions & Answers
277) About Informatica Power center 7: 1) I want to Know which mapping
properties can be overridden on a Session Task level. 2)Know what types of
permissions are needed to run and schedule Work flows.
Ans) 1.(Ans) You can override any properties other than the source and targets.
Make sure the source and targets exists in ur db if it is a relational db. If it is a flat
file, you can override its properties. You can override sql if its a relational db,
session log, DTM buffer size, cache sizes etc.

2.(Ans) You need execute permissions on the folder to run/schedule a workflow. You
may have read and write. But u need execute permissions as well.

278) Two relational tables are connected to SQ Trans,what are the possible errors
it will be thrown?
Ans) The only two possibilities as of I know is

Both the table should have primary key/foreign key relation ship
Both the table should be available in the same schema or same database

279) What r the options in the target session of update strategy transsformatioin?
Ans) Update as Insert:
This option specified all the update records from source to be flagged as inserts in
the target. In other words, instead of updating the records in the target they are
inserted as new records.
Update else Insert:
This option enables informatica to flag the records either for update if they are old
or insert, if they are new records from source.
insert,update,delete,insert as update,update else insert.update as update.

280) Why we use partitioning the session in informatica?
Ans) Performance can be improved by processing data in parallel in a single session
by creating multiple partitions of the pipeline.
Informatica server can achieve high performance by partitioning the pipleline and
performing the extract , transformation, and load for each partition in parallel.

281) I have a source column data with names like ravi kumar.i want to insert the
ravi in one column and kumar in another coliumn of target table.how do u
implement in informatica?
Ans) i can able to give solution for this Question , in Exp Transformation using
syntax of "substr" and "instr". use the syntax of this to identity the string when
source is having multiple string. i have given that Syntax below:
SUBSTR(char as char, m as numeric, [n as numeric])
//Returns n characters of char, beginning at character m.
INSTR(char1 as char, char2 as char, [n as integer, [m as integer, [comparisonType
as integer]]])
//Searches char1 beginning with its nth character for the mth occurance of char2
and returns the position of the character in char1 that is the first character of this
occurrence. Linguistic comparison is done when comparisonType is 0 and binary
comparison is done when comparisonType is any non-zero value. By default
comparisonType is 0 i.e.linguistic comparison
and use the link to get how achieved that Q in the below Link which contain
Source,Target code,mapping.




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                 Informatica Questions & Answers

282) DOubts regarding rank transformation: CAn we do ranking using two ports?
can we rank all the rows coming from source, how?
Ans) Rank port. Use to designate the column for which you want to rank values. You
can designate only one Rank port in a Rank transformation. The Rank port is an
input/output port. You must link the Rank port to another transformation.
So you can not use two ports for ranking in the rank transformation.
Note:you can achieve this question using Aggregate and Expression transformation.

283) what is the diff b/w rowid and row? 2.diff b/w rowid and row number?
Ans) Every row is identified by a rowid. ROWID is pseudo column in every table. The
physical address of the rows is use to for the ROWID.IN HEXADECIMAL
representation, ROWID is shown as 18 character string of the following format
BBBBBBBBB.RRRR.FFFF (block,row,file)
And row is a piece of record or simple a record.




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