An Introduction to DB2

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An Introduction to DB2 Powered By Docstoc
					ADABAS Versus DB2




An Evaluative Study by Butler Bloor Group
The DBMS Marketplace

n The OLTP Database
   u used for production data
   u designed for the production logic flow

n The Operational Data Mart
   u similar to the OLTP DB in Structure & Volume
   u used for heavy production-oriented query activity

n The Data Warehouse
   u Data Volume is much larger than in OLTP DB
   u Neutral Data Structures for Data Mining/Trawling
ADABAS Ratings

Performance-large OLTP                            10
                                                       EASE OF USE ***
Performance-large query                           10

Performance (General)                         9
                                                       UTILITIES *****
Database Functionality                7
                                                       DEVELOPMENT
Data Integration                              9        TOOLS *****
Distributed Features                          9

Server Architecture                           9

Portability                               8

                          1 2 3 4 5 6 7 8 9 10




                   IBM Mainframe Database Ratings
DB2 Ratings

                              DB2
 Performance-large OLTP                     8
                                                    EASE OF USE **
Performance-large query                         9

Performance (General)                   7
                                                    UTILITIES ****
Database Functionality              6
                                                    DEVELOPMENT
Data Integration                        7           TOOLS **
Distributed Features                    7

 Server Architecture                        8

 Portability                        6

                          1 2 3 4 5 6 7 8 9 10



                   IBM Mainframe Database Ratings
Performance


n DB2 has a history of performance problems and IBM
  has historically addressed it by throwing more
  hardware resources at DB2, specifically memory


n ADABAS’ major strength has always been
  performance, regardless of platform. We have
  numerous success stories and references to support
  this claim.
  Note the performance ratings on Butler Bloor study.
Resource Consumption

n Resource consumption is a major weakness of DB2.
  DB2 is not only mainframe and memory hungry, it is a
  DASD eater as well because it stores data
  uncompressed


n ADABAS has always proven to be a cost effective
  database solution, requiring limited hardware
  resources. Unlike DB2, the ADABAS nucleus needs
  only 1 region to run in and, because of ADABAS’
  unique ability to compress data, it is stingy on DASD
  resources
Relational Flexibility


n This is one area where DB2 shines. From the end
  user’s perspective, as well as for data modeling, the
  relational model greatly simplifies the concept of data
  storage and access


n ADABAS also supports the relational model.
  Moreover, ADABAS can support a wide variety of data
  models which can add flexibility and performance
Development Productivity

n Most of the DB2 related software products currently on
  the market focus on performance and tuning, system
  monitoring and database administration. CASE tools
  have failed miserably to provide productivity gains.
  Other offerings are limited to query tools


n Software AG has two different solutions for the
  productivity issue with NATURAL for DB2 as well as
  NATURAL for ADABAS
Desktop Access


n DB2 offers a superior solution in this category. Due to
  DB2’s market presence, and its support of SQL, there
  are a wide variety of desktop solutions for accessing
  DB2 data


n With the ADABAS SQL Server and ODBC driver
  interface we are able to provide direct access to
  ADABAS data via ODBC compliant desktop tools
Other Issues



n MUs and PEs: ADABAS has them, DB2 doesn’t
n Binding: Precompiling and binding a program
  package for DB2
n Read-thru-locks: An option with DB2, the norm with
  ADABAS
Other Issues Cont’d

n Field lengths: Can’t change them in DB2, can in
  ADABAS as long as it is not FIXED format


n Database Reorganizations: In DB2 you cannot
  reorganize at the table level, only at the DB level.
  ADABAS allows you to do both
   u Reorders on Simple Tablespaces in DB2 don’t help
     anyway because the rows from other tables are
     intermingled
Other Issues Cont’d


n Reorganizations (cont’d): When you drop a tablespace
  in DB2, that space is not available until the next
  Reorganization. If you delete a file in ADABAS, the
  space can be reused immediately


n Row overflow: Rows can span a page in DB2, but
  causes overhead if it does. Records cannot span
  blocks in ADABAS
Other Issues Cont’d



n The 3 “R’s” of DB2: Reorganization, Runstats,
  Rebind. ADABAS needs only the first “R” and
  you’re ready to go
n Backups: DB2 does not copy indexes with backups.
  You must recover them separately. ADABAS
  includes both index and data in the backup
Other Issues Cont’d



n Data Compression: DB2 doesn’t do it, unless
  hardware compression is involved. Indexes are not
  compressed in DB2, nor is the catalog. DASD saving
  compression has always been a part of ADABAS
  architecture

				
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posted:7/12/2013
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