Drop Baselines Hangs on Library Cache Lock (文档 ID 2186647.1)

In this Document


Symptoms

Cause

Solution

References


Applies to:

Oracle Database - Enterprise Edition - Version 12.1.0.2 and later
Information in this document applies to any platform.

Symptoms

  • Drop baselines hangs with library cache lock
  • If the baseline is being used, the library cache lock wait occurs. The baseline never drops.
  • If the baseline is not being used, the CPU wait occurs. The baseline never drops.
  • The more plans per query the longer it takes to drop. If there is only one plan, the plan drops in seconds. 

Cause

This is due to following bug:

Bug 20903742 : DBMS_SPM.DROP_SQL_PLAN_BASELINE ALLOCATES HUGE AMOUNT OF PGA MEMORY


But this Bug was closed as a duplicate of following bug:

Bug 20877664 : EXTRACTCLOBXML, REPEATING PREVIOUS VALUES FOR NULL INPUT
 

 

Solution

Apply patch 20877664.
 

References

BUG:20903742 - DBMS_SPM.DROP_SQL_PLAN_BASELINE ALLOCATES HUGE AMOUNT OF PGA MEMORY

NOTE:790039.1 - How to Drop Plans from the SQL Plan Management (SPM) Repository
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