High Waits for Latch 'qmn task queue latch'

Last updated on MAY 22, 2017

Applies to:

Symptoms

• High waits for "qmn task queue latch" on the database, the figures for other latches are much lower.
• 'Latch free' waits may or may not appear in the "Top 10 Foreground Events by Total Wait Time" waits of the AWR.
• AWR report show high activity on the "qmn task queue latch" in various sections:
  
  Latch Activity: - wait time is high
  
  
  
  
  
  Latch Sleep Breakdown: - High Sleeps
  
  
  
  

  Latch Miss Sources: - High Sleeps
  
  
  
  
  
  Parent Latch Statistics: - Sleeps and Spins are high
  

Cause