High SQ Enqueue Contention with LOBs or Advanced Replication (Doc ID 432508.1)

Last updated on DECEMBER 06, 2016

Applies to:

Oracle Database - Enterprise Edition - Version 9.2.0.1 and later
Information in this document applies to any platform.
***Checked for relevance on 09-Sep-2016***

Symptoms

You are seeing high contention for the SQ Enqueue in Statspack or AWR reports.
Examination of systemstate dumps reveals that the SQ enqueue most in contention is called SYS.IDGEN1$
Your application deals with LOBs or is using Advanced  Replication.
You may well be on RAC (although not a prerequisite to see this issue)

Cause

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