IF: Undo Related Wait Event - Latch: undo global data
(Doc ID 1951702.1)
Last updated on FEBRUARY 25, 2025
Applies to:
Oracle Database - Enterprise Edition - Version 9.2.0.1 and laterOracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Gen 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
Information in this document applies to any platform.
Symptoms
AWR report shows event latch: undo global data as the top wait event
Eg:
Top 5 Timed Foreground Events
Event Waits Time(s) Avg wait (ms) % DB time Wait Class
latch: undo global data 72,119,056 865,904 12 47.88 Other <<<
DB CPU 753,239 41.65
db file sequential read 57,249,544 118,554 2 6.55 User I/O
wait list latch free 1,767,054 17,961 10 0.99 Other
SQL*Net message from dblink 1,916,501 14,427 8 0.80 Network
Event Waits Time(s) Avg wait (ms) % DB time Wait Class
latch: undo global data 72,119,056 865,904 12 47.88 Other <<<
DB CPU 753,239 41.65
db file sequential read 57,249,544 118,554 2 6.55 User I/O
wait list latch free 1,767,054 17,961 10 0.99 Other
SQL*Net message from dblink 1,916,501 14,427 8 0.80 Network
Changes
Cause
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In this Document
| Symptoms |
| Changes |
| Cause |
| Solution |
| References |