Database Administrator's Guide

TRAN_INDEX_FLUSH_SEC

TRAN_INDEX_FLUSH_SEC <time_limit_in_seconds>

Sets the time limit in seconds that an index buffer can remain dirty before it is written to the file system cache.

Also, attempts to do routine optimization of index nodes as they are flushed to disk by background index flush. This is intended to improve overall index lookup performance and distinct key estimate accuracy.

Specify IMMEDIATE to cause dirty pages to be written immediately.
Specify OFF or -1 to disable the time limit-based flushing.
In V11.4 and later, a rate limiting parameter can be specified as follows: "rate=<msec> / <number of flushes>"
For example, to defer for 1 millisecond after every two flushes of updated TRNLOG data cache pages, use this option:
TRAN_DATA_FLUSH_SEC rate=1/2

System snapshot 19 and later includes fields referencing background flush state structure, BGFLSS, which is in the system snapshot structure, ctGSMS. When a background flush thread is set to flush at a particular rate, the text snapshot shows the rate. For example:

time limit for dirty non-transaction data pages : rate=1/1

This option can be changed using the ctSETCFG() API function or the ctadmn utility.

Note: Enabling this option disables checkpoint flush operations.

Default: -1 (disabled)