Bug 30846782 - 19c+ Fast/Excessive PGA Growth when Using dbms_stats.gather_table_stats in a Loop (Doc ID 30846782.8)

Bug 30846782 19c+ Fast/Excessive PGA Growth when Using dbms_stats.gather_table_stats in a Loop

This note gives a brief overview of bug 30846782.
The content was last updated on: 25-DEC-2020
Click here for details of each of the sections below.

Affects:

Product (Component) Oracle Server (Rdbms)

Range of versions believed to be affected Versions >= 19.1 but BELOW 21.1

Versions confirmed as being affected

19.9.0

19.8.0

19.7.0

19.6.0

19.4.0

19.3.0

19.1.0

Platforms affected Generic (all / most platforms affected)

Fixed:

The fix for 30846782 is first included in

19.10.0.0.DBRU:210119 (JAN 2021) DB Release Update Revision(DB RU)

Interim patches may be available for earlier versions - click here to check.

Symptoms:	Related To:
Leak (Memory Leak / Growth)	DBMS_STATS

Description

Growth in PGA memory usage when gather_table_stats gets executed in a PL/SQL loop (e.g. anonymous block).
The memory allocated during gather_table_stats() is getting freed at the end of anonymous/PLSQL block (user call).
 
 REDISCOVERY INFORMATION:
 1. Setting "_fix_control"='20424684:OFF' should not reproduce the problem.
 2. Issue should be growth in PGA memory (not a leak) while executing gather_table_stats()
  
 .
 WORKAROUND:
 alter session set "_fix_control"='20424684:OFF';
  
 .

Please note: The above is a summary description only. Actual symptoms can vary. Matching to any symptoms here does not confirm that you are encountering this problem. For questions about this bug please consult Oracle Support.

References

Bug:30846782 (This link will only work for PUBLISHED bugs)
Note:245840.1 Information on the sections in this article