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enq: MS - Contention During Materialized View Refresh (Doc ID 2366181.1)

Last updated on OCTOBER 16, 2019

Applies to:

Oracle Database - Enterprise Edition - Version 12.1.0.2 and later
Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Cloud Machine - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Cloud Exadata Service - Version N/A and later
Information in this document applies to any platform.

Symptoms

enq:MS - contention is seen during MV refresh, even though there is no MV log. The MV is doing complete refresh.

During refresh, application sessions experience enq: MS - contention when accessing the base objects of the materialized views, and this sometimes lasts long enough that it times out the session (from the application side).


Changes

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When an mview refresh operation takes place, one of the things that happen is: SYS.SNAP$ and SYS.MLOG$ are updated to show the time of refresh.

 

Cause

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In this Document
Symptoms
Changes
Cause
Solution
References


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