enq: MS - Contention During Materialized View Refresh
(Doc ID 2366181.1)
Last updated on JULY 22, 2021
Applies to:
Oracle Database - Enterprise Edition - Version 12.1.0.2 and laterOracle Database Cloud Schema Service - Version N/A and later
Gen 1 Exadata Cloud at Customer (Oracle Exadata Database 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 |