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Materialized View Refresh Takes Long Time & High Cpu Usage To Complete (Doc ID 727215.1)

Last updated on AUGUST 14, 2020

Applies to:

Oracle Database - Enterprise Edition - Version 10.2.0.3 and later
Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Cloud Machine - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Information in this document applies to any platform.

Symptoms

Problem Statement:
There are many cases where materialized view refresh is very slow without clear reasons. This article describes one of those cases. In this case, the refresh takes a lot of CPU and few hours to complete. However, the same materialized view query takes only a few minutes to complete if run outside the refresh.
Research showed that the INSERT generated by the REFRESH takes a long time while the same INSERT executed outside of the REFRESH runs quickly.

 

Changes

 

Cause

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In this Document
Symptoms
Changes
Cause
Solution
References

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