Replication Intrusions and Impacts

The Replication Agent DB2 libraries must be authorized by the authorized program facility (APF).

The performance and operation of DB2 UDB primary data servers in an SAP replication system may be affected as follows:

In the DB2 UDB transaction log:
- Replication requires a before and after image of each row that is changed. When you mark a primary table for replication, the table is altered with the DATA CAPTURE CHANGES clause. As the number of tables marked for replication increases, so does the DASD space requirement for the DB2 UDB active log data sets.
- Using Replication Agent for DB2 UDB increases the amount of data stored in DB2 UDB logs. The size of the increase depends on the number, type, and size of the primary tables, and the types of transactions replicated. For example, update transactions require both before and after images, and they include all of the columns in a row, even if those columns do not change. For more detailed information, see the Replication Agent for DB2 UDB documentation.
When you install the Replication Agent, two Replication Agent system tables are created in the primary DB2 UDB:
- LTMOBJECTS contains a row for each primary table marked for replication. Its size depends on the number of tables marked for replication.
- LTMMARKER, when updated, can be used to aid in the materialization process.
A task started in Replication Agent for DB2 UDB can process the log of a single DB2 subsystem, or all logs in a DB2 data sharing group. This behavior is controlled by LTMCFG parameters: DataSharingOption, DataSharingMember, Log_identifier, and BSDS.
Primary database limitations:
- LOB replication is not supported.
- charand varchar maximum size is 32767.
- DDL and stored procedure replication is not supported.
Do not use these DB2 UDB utilities, as doing so may jeopardize replication integrity:
- LOAD LOG NO
- RECOVER
- REORG with RECOVER
rs_ticket cannot be started in Replication Agent DB2 UDB. In Replication Server 15.5, it is possible to “inject” the rs_ticket into a Replication Agent DB2 connection. See Replication Server Reference Manual > Replication Server Commands > sysadmin issue_ticket.