12.2: Drop Materialized View Is Very Slow or Hangs

(Doc ID 2401976.1)

Last updated on MAY 29, 2018

Applies to:

Oracle Database - Enterprise Edition - Version 12.2.0.1 and later
Information in this document applies to any platform.

Symptoms

Enabling 10046 trace for the 'drop mview' command shows high waits for the following query which actually does Delete operation on this table - "SYS.MVREF$_CHANGE_STATS"

DELETE FROM SYS.MVREF$_CHANGE_STATS
WHERE
REFRESH_ID = :B2 AND MV_OBJ# = :B1;

 

Changes

This is because, Up to 11g, there was no usage tracking for MVIEW operations. But, starting from 12.2, the usage tracking for MVIEW operations is implemented.

Cause

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