| memory issues when switching to cbo [message #55307] |
Thu, 16 January 2003 12:25  |
Rich Hooper
Messages: 1
Registered: January 2003
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Junior Member |
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Right now my 8.1.7 db is initialized at CHOOSE. There are no statistics on any of the tables so I am getting RULE. I would like to start using the CBO but after generating statistics for the schema my available physical RAM starts falling. After a few hours the memory gets so low that I have to delete the statistics. Then the memory comes back. About a gig almost instantaneously and then after a couple of hours I get back to my usual steady state of about 5 gig free. The box has 32 gig total with 16 of that for the SGA. Any ideas what might be going on? Suggestions for debugging?
Thanks.
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| Re: memory issues when switching to cbo [message #55319 is a reply to message #55307] |
Fri, 17 January 2003 07:00  |
Sanjay
Messages: 236
Registered: July 2000
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Senior Member |
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Interesting ..
Couple of details will help:
1. What is your SORT_AREA_SIZE ?
2. Do you have an explain plan before (choose, which uses RBO) and after (cbo - all_rows, first_row) ? Look for FULL TABLE SCANs.
3. How is your usage of TEMP tablespace ?
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