Oracle FAQ | Your Portal to the Oracle Knowledge Grid |
![]() |
![]() |
Home -> Community -> Mailing Lists -> Oracle-L -> RE: Caching a huge table's data in memory
Searched the site and found nada relating to this topic. Are you saying
something in that paper (wherever it is) contradicts the below, like cache
tables ARE pinned in memory? Is this just a general recommendation or do you
have specifics about how it relates to the topic at hand? ;-)
TIA
-----Original Message-----
Sent: Tuesday, January 07, 2003 10:44 AM
To: Multiple recipients of list ORACLE-L
Read Cary Millsap's papers on Misunderstandings about Oracle Internals at his site www.hotsos.com <http://www.hotsos.com> . They are excellent!
-----Original Message-----
Sent: Tuesday, January 07, 2003 9:54 AM
To: Multiple recipients of list ORACLE-L
I don't think a cache table is actually "pinned" in memory. It just means
that its blocks stick around once they are read and are not recycled as
much as "normal" tables. That having been said, due diligence should be
taken to tune the queries and caching large tables should be avoided. What
good is it if you "tune", or rather, speed up one query if it takes
resources
away from other queries and slows down the overall system? Sounds like a
good opportunity to educate a DUHveloper. Tune the query and show her/him
before and after tkprof stats. Better yet, teach her/him how to use tkprof
and make them run it on each query before putting it into code. Make sure
your test/development data set reflects production volumes.
Steve Orr
Bozeman, Montana
-----Original Message-----
Sent: Tuesday, January 07, 2003 8:09 AM
To: Multiple recipients of list ORACLE-L
Pro: It is in memory
Con: You must buy the memory. You must be sure you don't cause the box to start paging to swap ... very bad ... VERY bad.
When you live in the land of bad applications, sometimes the politics of the
situation are such that you just do what you know is the equivalent of "fixing" things with duct tape -- a whole lot of duct tape -- rather than attempt to engage in a hopeless fight. Consider the case of an application that is so bad that a box with more than 50 Gb of RAM and 16 Alpha CPU's are
required to handle from 6 to 10 active connections. Hey, if they want to spend the money ....
> -----Original Message-----
> What are the pros and cons of caching a table's data?
-- -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Orr, Steve INET: sorr_at_rightnow.com Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).Received on Tue Jan 07 2003 - 13:25:50 CST
![]() |
![]() |