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Home -> Community -> Mailing Lists -> Oracle-L -> RE: SGA
...You cache a few more blocks than just one. The pre-fetched blocks will be
cached (and, I think, pinned) as well.
Cary Millsap
Hotsos Enterprises, Ltd.
http://www.hotsos.com
* Nullius in verba *
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-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org]
On Behalf Of Justin Cave
Sent: Wednesday, June 23, 2004 9:56 PM
To: oracle-l_at_freelists.org
Subject: RE: SGA
I would hope that none of the SGA is free. If you can benefit from the memory allocated to the SGA, as opposed to allocating gobs of useless memory, what possible reason would Oracle have not to use it all?
For full table scans, Oracle always puts the blocks at the least recently used side of the buffer cache, so you only cache 1 block. If Oracle has to process more rows than it can cache, it simply ages out the older blocks.
Justin Cave
Distributed Database Consulting, Inc.
http://www.ddbcinc.com/askDDBC
-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org]
On Behalf Of Seema Singh
Sent: Wednesday, June 23, 2004 8:01 PM
To: oracle-l_at_freelists.org
Subject: SGA
Hi,
How much in general % SGA should be free ? If table size is in 1GB or more
and sga is 80mb how oracle will process the full scan of that particular
table?
thx
-Seema
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