High Waits for Latch 'qmn task queue latch'
(Doc ID 2054781.1)
Last updated on JULY 04, 2021
Applies to:
Oracle Database Cloud Schema Service - Version N/A and laterGen 1 Exadata Cloud at Customer (Oracle Exadata Database Cloud Machine) - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Oracle Database Backup Service - Version N/A and later
Information in this document applies to any platform.
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
Changes
Cause
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In this Document
| Symptoms |
| Changes |
| Cause |
| Solution |
| References |