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What Causes "ORA-12800: system appears too busy for parallel query execution"? (Doc ID 2954651.1)

Last updated on OCTOBER 17, 2023

Applies to:

Oracle Database - Enterprise Edition - Version 19.11.0.0.0 and later
Information in this document applies to any platform.

Symptoms

A parallel query failed with "ORA-12800: system appears too busy for parallel query execution."  In this case, the query that got the error ran in about 13.08ms, according to the sqlmon.  At the time of issue, the sql_id was seen to have executed in parallel about 3,484,728 times in 9 minutes from concurrent sessions; about 6,453.2 times a second, using 8 parallel-slave processes for each execution.  The number of executions included those from the SQL's subqueries.

Changes

 Upgrade to 19.11 Database Release Update or higher.

Cause

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In this Document
Symptoms
Changes
Cause
Solution


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