Preparing for Oracle Streams Replication

Before configuring Oracle Streams replication, prepare the databases that will participate in the replication environment.

To prepare for Oracle Streams replication: 

1. Set initialization parameters properly before you configure a replication environment with Oracle Streams:

   • Global Names: Set the GLOBAL_NAMES initialization parameter to TRUE at each database that will participate in the Oracle Streams replication environment. See "Setting the GLOBAL_NAMES Initialization Parameter to TRUE".

   • Compatibility: To use the latest features of Oracle Streams, it is best to set the COMPATIBLE initialization parameter as high as you can. If possible, then set this parameter to 11.2.0 or higher.

   • System Global Area (SGA) and the Oracle Streams pool: Ensure that the Oracle Streams pool is large enough to accommodate the Oracle Streams components created for the replication environment. The Oracle Streams pool is part of the System Global Area (SGA). You can manage the Oracle Streams pool by setting the MEMORY_TARGET initialization parameter (Automatic Memory Management), the SGA_TARGET initialization parameter (Automatic Shared Memory Management), or the STREAMS_POOL_SIZE initialization parameter. See Oracle Streams Replication Administrator's Guide for more information about the Oracle Streams pool.

     The memory requirements for Oracle Streams components are:

     • Each queue requires at least 10 MB of memory.

     • Each capture process parallelism requires at least 10 MB of memory. The parallelism capture process parameter controls the number of processes used by the capture process to capture changes. You might be able to improve capture process performance by adjusting capture process parallelism.

     • Each propagation requires at least 1 MB of memory.

     • Each apply process parallelism requires at least 1 MB of memory. The parallelism apply process parameter controls the number of processes used by the apply process to apply changes. You might be able to improve apply process performance by adjusting apply process parallelism.

   • Processes and Sessions: Oracle Streams capture processes, propagations, and apply processes use processes that run in the background. You might need to increase the value of the PROCESSES and SESSIONS initialization parameters to accommodate these processes.

2. Review the best practices for Oracle Streams replication environments and follow the best practices when you configure the environment. See Oracle Streams Replication Administrator's Guide for information about best practices.

   Following the best practices ensures that your environment performs optimally and avoids problems. The Setup Streams Replication Wizard in Oracle Enterprise Manager and the configuration procedures in the DBMS_STREAMS_ADM package follow the best practices automatically. However, if you plan to configure an Oracle Streams replication environment without using the wizard or a configuration procedure, then learn about the best practices and follow them whenever possible.

   The following are some of the important best practices to follow during Oracle Streams configuration:

   • Configure a separate tablespace for the Oracle Streams administrator. The instructions in "Tutorial: Configuring an Oracle Streams Administrator" follow this best practice.

   • Use separate queues for capture processes, synchronous captures, and apply processes. For the best performance, these components typically should not share a queue.

   • Use queue-to-queue propagations.

   After the Oracle Streams environment is configured, the following are some of the important best practices to follow for operation of the Oracle Streams environment:

   • Monitor performance and make adjustments when necessary.

   • Monitor queues for size.

   • Follow the Oracle Streams best practices for backups.

   • Check the alert log for Oracle Streams information.

   • Set capture process parallelism for best performance.

   • Set apply process parallelism for best performance.

   • Check for apply errors and manage them if they occur.

See Oracle Streams Replication Administrator's Guide for detailed information about these best practices, and for information about other Oracle Streams best practices.