Common Cause for ORA-4031 in 10gR2, Excess "KGH: NO ACCESS" Memory Allocation [Video]
Last updated on NOVEMBER 28, 2016
Applies to:Oracle Database - Enterprise Edition - Version 10.2.0.1 to 10.2.0.5 [Release 10.2]
Information in this document applies to any platform.
***Checked for relevance on 27-Jan-2016***
Video - How to determine you are hitting this issue (02:44)
After several hours of database operation, ORA-4031 errors are reported.
An examination of the ORA-4031 trace file will show the Memory Allocation called "KGH: NO ACCESS" is consuming large amount of memory. For example the following shows over 500Mbytes for this allocation.
Allocation Name Size_________________________ __________"free memory " 163766600 ..."KGH: NO ACCESS " 560713888
Note that it is normal to periodically see "KGH: NO ACCESS" allocations up to about 64M.
This is memory that is in transition between SGA components when automatic memory management is resizing SGA components. However, it is not normal to see persistent high allocations or a steady build up of this allocation type over time. The exception is when the database needs to make large changes i.e. when changing memory after a heavy load, or starting up using sub-optimal SGA settings, such as when an SPFILE is not being used.
The following query confirms that Memory Allocation "KGH: NO ACCESS" is large:
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