UORGROUPCOUNT

The UORGROUPCOUNT parameter identifies the number of messages that the capture service should group into a common unit of recovery (UOR) during replication.

Description

The source server, by default, respects the transaction boundaries of the source database managements system (DBMS) and replicates transactions within those boundaries. This means that each transaction is individually managed at the target server.

For small transactions, you might achieve higher throughput and lower CPU by grouping multiple small transactions into a single larger transaction. You can use the UORGROUPCOUNT parameter to instruct the source server to combine smaller transactions together before they are sent to the target server.

The UORGROUPCOUNT parameter represents the maximum number of updates to group together. The source server combines transactions until the number of updates will exceed the UORGROUPCOUNT value if the next transaction is grouped. At this point, the group is sent to the target server and a new group is started. A group is also completed and a new group is started when the following situations occur:
  • The source server runs out of committed work in the capture cache
  • The group is serial and the next UOR is parallel, or the group is parallel and the next UOR is serial

Grouping transactions with the UORGROUPCOUNT parameter does not cause an original transaction from the source DBMS to be divided into multiple groups. An original transaction is always contained in a single group when transaction grouping is active.

Specifications

Use: Configuration parameter for the capture service.

Service class: CAP

Task name: CECCAP

Data type: INT

Default: 1

The default value indicates that transaction grouping is inactive because each transaction meets or exceeds the UORGROUPCOUNT value and causes the UOR to be sent to the target.