Logical Log Configuration Guidelines

Logical logs must be configured correctly for Enterprise Replication.

Use the following guidelines when configuring your logical log files:
  • Make sure that all logical log files are approximately the same size.
  • Make the size of the logical log files large enough so that the database server switches log files no more than once every 15 minutes during normal processing.
  • Plan to have sufficient logical-log space to hold at least four times the maximum transaction size.
  • Set LTXEHWM (long-transaction, exclusive-access, high-watermark) 30 percent larger than LTXHWM (long-transaction high-watermark).
Important: If you specify that the database server allocate logical log files dynamically (DYNAMIC_LOGS), it is recommended that you set LTXEHWM to no higher than 70 when using Enterprise Replication.

For more information about logical logs and these configuration parameters, see HCL OneDB™ Administrator's Reference and HCL OneDB Administrator's Guide.

The database server can add logs dynamically when Enterprise Replication approaches a potential log wrap situation if the CDR_MAX_DYNAMIC_LOGS configuration parameter is set to a non-zero integer.