Re: Oracle and Memory

Joel Garry (joelga_at_rossinc.com) wrote:
: In article <4utgiv$o6a_at_nntp.interaccess.com> andre_at_interaccess.com (Andre T. Allen) writes:
: >In article <4usk08$p7s_at_newsserv.cs.sunysb.edu>, trubisz_at_cs.sunysb.edu (Joe Trubisz) wrote:
: >>This might sound like a totally idiotic question, since it
: >>flys in the face of reason. But, an associate of mine just
: >>came back from a Oracle class where the statement was made that
: >>'having too much memory can cause problems with Oracle'. I
: >>thought that this was totally absurd and the person in the
: >>class didn't ask the obvious question, why?
: >>
: >>Does this make sense to anyone or was the instructor out to lunch?
: >>
: >>Thanks,
: >>Joe
: >>
: >
: >Too Much memory? In the day and age where it's slowly becoming chic to cache
: >a whole database in memory, "too much" memory seems somewhat absurd.
: >
: >I have however, heard of instances where too much memory was allocated to the
: >Oracle shared pool. This may result in some performance degradation if the
: >shared pool is so big that it would actually take longer to search the shared
: >pool for a cached SQL statement than it would be for the statement to be
: >re-parsed and executed.
 

: And if the SGA is so big it causes swapping, while a big part of the SGA
: isn't even being used, that is certainly too much memory. That will
: cause problems.
 

: select sum(gets), sum(getmisses) from V$ROWCACHE.
: if sum(getmisses)/sum(gets) << .1, you have allocated too much memory to
: the data dictionary and library caches. Probably won't cause problems,
: but a waste of an expensive resource better allocated to users.
 

: >
: >Is this person going to Oracle Education, or to a 3rd party? I have heard
: >some stories about certain instructors not knowing their a$$ from a hole in
: >the ground.
: >
: >Regards -
: >
: >***************************************************************
: >** Andre T. Allen * andre_at_interaccess.com **
: >** SysAdmin/DBA * 74262.3572_at_compuserve.com **
: >** Reid Psychological Systems * 312.938.9200 (Voice) **
: >** Chicago, IL * 312.294.0104 (Fax) **
: >***************************************************************

: --
: Joel Garry joelga_at_rossinc.com Compuserve 70661,1534
: These are my opinions, not necessarily those of Ross Systems, Inc. <> <>
: %DCL-W-SOFTONEDGEDONTPUSH, Software On Edge - Don't Push. \ V /
: panic: ifree: freeing free inodes... O
Received on Fri Aug 23 1996 - 00:00:00 CEST