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Key: QA-8
Type: Oracle - Internals Oracle - Internals
Status: Closed Closed
Resolution: Answered
Priority: Major Major
Assignee: ubTools Support
Reporter: ubTools Support
Votes: 0
Watchers: 0
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Heapdump Interpretation

Created: 15/Jul/07 12:58 PM   Updated: 16/Sep/07 04:30 PM
Fix Version/s: None

Product Version: ???
Operating System: Generic


 Description  « Hide
I have a process which is taking up way more memory than I'd expected. The process runs a PL/SQL that does some nested loop joins on a PL/SQL table.

The background process is using > 200Mb of private memory and this number goes up if we tweak the WHERE clause in the join to return more data.

I did a heapdump of the process and the trace file looks like this (lots of stuff trimmed):

 
...
EXTENT 437
Chunk 925dfe4 sz= 1836 perm "perm " alo=1836
Chunk 925e710 sz= 1156 recreate "session heap " latch=0
ds 92693fc sz= 30315156 ct= 440
b7aa56c sz= 3980
92f30a0 sz= 1072
afb6e34 sz= 16472
afb2dcc sz= 16472
afaed64 sz= 16472
...

I presume that "session heap" is the UGA for this process'
session. Basically it goes on like this for several pages with sz anywhere between 16k and 1Mb. How can I interpret this? I presume the memory is to do with cursor information. This is a sort but the sort area size is only 10Mb and cannot account for all the private memory in use.

I'm just trying to decide if this is a reasonable amount of memory to be using (i.e. explain what it is using it for) and just put up with it, or if something has gone wrong. I'm on 8.1.5 on Linux 2.2 (I know, I know...)

Thanks for any insight!



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Change by ubTools Support - 15/Jul/07 01:03 PM
Field Original Value New Value
Status Open [ 1 ] Closed [ 6 ]
Resolution Answered [ 10 ]

Change by ubTools Admin - 16/Sep/07 04:20 PM
Resolution Answered [ 10 ]
Status Closed [ 6 ] Reopened [ 4 ]

Change by ubTools Admin - 16/Sep/07 04:20 PM
Issue Type Problem [ 1 ] Oracle - Internals [ 8 ]

Change by ubTools Support - 16/Sep/07 04:30 PM
Resolution Answered [ 10 ]
Status Reopened [ 4 ] Closed [ 6 ]