12c RAC DDL Performance Issue: High "enq: IV - contention" etc if CPU Count is Different (Doc ID 2028503.1)

Last updated on JANUARY 27, 2017

Applies to:

Oracle Database - Enterprise Edition - Version 12.1.0.1 to 12.1.0.2 [Release 12.1]
Information in this document applies to any platform.

Symptoms

12c RAC database seeing high "enq: IV - contention":


From awr report:

Top 10 Foreground Events by Total Wait Time
===================================
Event Waits Total Wait Time (sec) Wait Avg(ms) % DB time Wait Class
enq: IV - contention 52,914 1688.4 31.91 42.8 Other
row cache lock 44,865 896.8 19.99 22.7 Concurrency

 

tkprof of 10046 trace of SQL statement shows the same event in the top:

Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
enq: IV - contention 6017 0.32 287.68
row cache lock 957 0.20 7.48
library cache lock 631 0.13 15.10
library cache pin 616 0.11 14.54

 

 

Cause

Sign In with your My Oracle Support account

Don't have a My Oracle Support account? Click to get started

My Oracle Support provides customers with access to over a
Million Knowledge Articles and hundreds of Community platforms