Mark Gurry

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					MGA Duplica

Replication Tool
     Why Replication?
1.   High Availability and Avoidance of Data Loss
        Replicate to alternate databases
2. Split activities across databases (one database
     OLTP and the other Reports)
        It is often difficult to achieve acceptable performance when
         OLTP users are mixed with Report users
3.   Populate Web databases outside main OLTP
        The main database must be secure
     Why Replication?
4.   Simplification
        Summarisation and aggregation of data to speed performance
         and reduce development and maintenance time
        Similar to materialized views but without the performance and
         administration overhead of the materialized view logs and
         without the restrictions of the materialized views
5.   Disaster Recovery
        Populate a Disaster Recovery Database
        Some sites also use the DB for reporting
        Decoupling for High Availability
            Avoids one database going down impacting others when
             database links are used

 Source                                Web
Database       Firewall

  Why Duplica?

1. Reliable Replication
   Duplica has been replicating from the mission critical
     24 * 7 Australian Electricity market database to 38
     external power companies for many years
   A wide variety of site use the product
   Proven technology used by banks, stock exchanges
     and other companies with large volumes of
  Why Duplica?

2. Fast Replication with little impact on
   source database
     Replicates in parallel using multi-threading and array
     Benchmarks indicate 18,000,000 inserts and 3,000,000
      updates and deletes per hour for each thread
     You can set a row limit to ease the impact of the data
  Why Duplica?

3. Versatility
   Runs beautifully on RAC

   Runs on any operating system that the Oracle
    RDBMS supports
   Can also replicate to SQL*Server
 Why Duplica?

4. Allows staggered replication
   Protects your network and source database
   Replicate critical data right now and non critical data
   Allows real time replication on all critical tables
  Why Duplica?

5. Vertical and Horizontal partitioning
     Why replicate all the data when only certain columns and
      rows are required
     Allows the enforcement of security with sites being
      replicated to only replicating data that they are entitled to
     Allows you to encrypt data for confidentiality
     Allows you to selectively replicate your regional data, for
      example, replicate Californian data to your local database
      from the national database
  Why Duplica?

6. Fast failover and failback
   Have choice of timestamp replication or log based
   Both allow you to easily see data that is missing after
     a failover and failback
   You cannot lose data with Duplica based replication
 Why Duplica?

6. Simplifies Change Management
   Dynamically generates the SQL to insert, update and
     delete at the source database, bringing only the
     columns that it needs
   This allows delayed applying of DDL at the target
 Why Duplica?

7. Easy Administration
   Turning tables to replicate on and off is a breeze

   The product runs in robot mode with many sites
     running the product without a DBA
   Duplica contains extensive health checks and
     auditing when they are required
The Duplica Architecture
    The Architecture
•   Duplica uses Suites to Replicate data
    •   You enter Related Tables into a Suite

•   You will typically have many Suites
•   Tables are given a sequence within the Suite to
    indicate the order of replication
    •   Must maintain referential integrity

•   Suites can be replicated at different intervals
    The Architecture
•   Duplica detects the data to replicate using
    •   A LOG table that is populated by a trigger
    •   Using a Timestamp column on the source tables (if
        one exists)

•   If rows are deleted from tables, you must use
    the LOG table approach
    The Architecture
•   Sample LOG table

    (      DML_TIMESTAMP               DATE
    ,      DML_COPY                    VARCHAR2(1)
    ,      DML_OPERATION               VARCHAR2(1)
    ,      DML_COUNT                   NUMBER
    ,      SYS_DB_ID                   NUMBER
    ,      SYS_PROD_ID                 NUMBER
    The Architecture
•   Duplica in installed into the Target Database
•   The installation includes a number of tables, indexes,
    views, sequences and stored procedures
•   Data is pulled from source to the target using the
    PL/SQL stored procedures
•   Duplica uses a Delphi front end
•   Multiple DBAs may have the front end installed in their
    PCs. They will all access the same Duplica objects in the
    target databases
•   DBMS_JOBS is used to schedule the replication of
    The Architecture
•   Some sites replicate from one database to
    another and then from the target database to a
    3rd database
•   This is used for Disaster Recovery as well as
    creating multiple User Acceptance or Test
    Database with real data
The User Interface
                                     Audit the row counts at the
Suites are set up with one           Source and target database
or more tables

                             Schedule and unschedule
                             the suite with ease
 Place tables into suite

   Timestamp column

Download order
provides referential
  Place your WHERE
  criteria here for the
  table. You can also
  replicate from views
Duplica puts replication, database and error and audit logs
at your fingertips