Higher Library Cache Latch contention in 10g than 9i

(Doc ID 463860.1)

Last updated on SEPTEMBER 19, 2016

Applies to:

Oracle Server - Enterprise Edition - Version: 10.1.0.2 to 10.2.0.3 - Release: 10.1 to 10.2
Information in this document applies to any platform.
Version: 10.1.0.2 to 10.2.0.3

Symptoms

Recently database server 10.x was upgraded from 9.x (or an earlier release) and high waits for Library Cache Latch is noticed.  No changes have been made--spfile parameters, workload, etc to affect library cache load.

CURSOR_SHARING=SIMILAR is used and also was used  in 9.x.

The default value for bind peeking has not been changed which is TRUE and is an underscore parameter.

The automatic statistics gathering in 10.x has not been changed:

SQL> SELECT STATE FROM DBA_SCHEDULER_JOBS WHERE JOB_NAME = 'GATHER_STATS_JOB';

STATE
---------------
SCHEDULED

AWR or Statspack reports show some SQL with a high Version Count which was not the case in 9.x.

Changes

Migrated from 9i or earlier version to 10g.

Cause

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