11gR2/Aix - Dedicated Server Processes Have Large Usla Heap Segment Compared To Older Versions (Doc ID 1260095.1)

Last updated on SEPTEMBER 28, 2016

Applies to:

Oracle Database - Enterprise Edition - Version 11.2.0.1 to 11.2.0.4 [Release 11.2]
IBM AIX on POWER Systems (64-bit)

Symptoms

Dedicated server processes using significantly more memory on 11gR2 compared to previous versions (9i, 10g, 11g).

Using svmon to monitor process memory segment after initial DB connection, You can observe that typical USLA heap size jumped from ~0.4M in 10g to 7.0M in 11gR2.

svmon -P PID - where PID is an Oracle process id

Oracle Release -> (work USLA heap times 4k pages size)

11.2.0.1.0 -> 7M bytes
11.1.0.7.0 -> 60KB
10.2.0.4.0 -> 420KB

Slow system performance for larger footprint of all oracle server process. If physical memory is fully used, the could terminate an Oracle instance via terminating a PMON process.

 

Changes

Upgraded to 11gR2

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