OFF_RECVRY_THREADS configuration parameter

Use the OFF_RECVRY_THREADS configuration parameter to specify the number of recovery threads that are used for logical recovery during a cold restore or fast recovery.

onconfig.std value
OFF_RECVRY_THREADS 10
values
Positive integers
units
Number of recovery threads that run in parallel
takes effect
After you edit your onconfig file and restart the database server.

Usage

Before you perform a cold restore, you can set the value of this parameter to approximately the number of tables that have many transactions against them in the logical log. For single-processor computers or nodes, more than 30 to 40 threads might be too many because the cost of thread management and memory offsets the increase in parallel processing.

Whenever logical recovery begins, the database server creates an LGR memory pool for the recovery threads. The size of the LGR memory pool is approximately equal to the value of OFF_RECVRY_THREADS * 100 KB. This pool is used during fast recovery and during cold restores. Do not set the OFF_RECVRY_THREADS configuration parameter to a value that results in the database server attempting to allocate more memory for the LGR memory pool than is available on your system.

In a high-availability cluster, a secondary server is almost always in fast recovery mode. On secondary servers, set the OFF_RECVRY_THREADS configuration parameter to a value that takes both roll-forward performance and memory usage into account.


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