On Jul 2, 8:49 am, Charles Hooper <hooperc2..._at_yahoo.com> wrote:
> On Jul 2, 5:33 am, zigzag..._at_yahoo.com wrote:
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> > On Jul 2, 5:29 am, zigzag..._at_yahoo.com wrote:
> > > On Jul 1, 10:47 pm, Charles Hooper <hooperc2..._at_yahoo.com> wrote:
>
> > > > On Jul 1, 12:37 pm, zigzag..._at_yahoo.com wrote:
>
> > > > > On Jul 1, 11:41 am, sybra..._at_hccnet.nl wrote:
> > > > > > Apart from that cranking up the memory won't resolve your fundamental
> > > > > > problem: apparently you never tuned your application and now you want
> > > > > > to resolve that by throwing memory at the problem.
> > > > > > This method has been demonstrated to be fundamentally wrong over and
> > > > > > over again, and is one of the safest methods to end up in hell or at
> > > > > > the unemployment office.
>
> > > > > > --
> > > > > > Sybrand Bakker
> > > > > > Senior Oracle DBA-
>
> > > > > FYI, keep and recycle pools work exactly the same way. keep and
> > > > > recycle are just the names given by Oracle. Vendor sells the
> > > > > application, I cannot do any tuning of application.
>
> > > > The above comment is interesting. I recall reading in several places
> > > > that the keep pool tries to keep blocks in memory, much like the
> > > > default pool, while the recycle pool tries to quickly age blocks out
> > > > of the pool. After a bit of a search, I found a bit of disagreement.
> > > > The results of the search follow:
>
> <snip>
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> > > > "Expert Oracle One on One" Page 80:
> > > > "We also have the ability to carve out a space for segments in the
> > > > buffer pool. This space is called the RECYCLE pool. Here, the aging
> > > > of the blocks is done differently to the KEEP pool. In the KEEP pool,
> > > > the goal is to keep 'warm' and 'hot' blocks cached for as long as
> > > > possible. In the recycle pool, the goal is to age out a block as soon
> > > > as it is no longer needed."
>
> > > >http://www.jlcomp.demon.co.uk/faq/pin_table.html
> > > > "NOTE: there is no difference in the behavior of the three buffer
> > > > pools, the naming of the pools is merely for memo technically reasons
> > > > and intended use."
>
> > > >http://forums.oracle.com/forums/thread.jspa?threadID=524119-lookfor
> > > > the posting by Jonathan Lewis for context:
> > > > "You will rarely be able to beat Oracle's caching algorithms by
> > > > playing with KEEP and RECYCLE pools - but there are a few special
> > > > cases..."
>
> > > > Charles Hooper
> > > > IT Manager/Oracle DBA
> > > > K&M Machine-Fabricating, Inc.
> > > >> "NOTE: there is no difference in the behavior of the three buffer
>
> > > pools, the naming of the pools is merely for memo technically reasons
> > > and intended use."
>
> > > This is exactly what I meant in my first post.>
>
> >http://www.jlcomp.demon.co.uk/faq/pin_table.html
> > "NOTE: there is no difference in the behavior of the three buffer
> > pools, the naming of the pools is merely for memo technically reasons
> > and intended use."
>
> > This is exactly what I meant in my first post.-
> > Just because you put a table in recycle pool instead of keep. Oracle
> > is not going to treat it any differently.
>
> A bit more searching in books finds two different opinions on how the
> different buffer caches operate:
> "Expert Oracle Database 10g Administration" page 123:
> "Keep buffer pool: Keeps the data blocks in memory. You may have
> small tables that are frequently accessed, so to prevent them from
> being aged out of the database buffer cache, you can assign the tables
> to the keep buffer cache when they are created.
> Recycle buffer cache: Removes the data from the cache immediately
> after use. You need to use this buffer cache carefully, if you decide
> to use it at all. The recycle buffer cache will cycle out the object
> from the cache as soon as the transaction is over."
>
> "Expert Oracle Database Architecture" page 141:
> "In fact, the three pools manage blocks in a mostly identical fashion;
> they do not have radically different algorithms for aging or caching
> blocks. The goal here was to give the DBA the ability to segregate
> segments to hot, warm, and do not care to cache areas."
>
> The first of the above quotes seems to be in agreement with Tom Kyte's
> "Expert Oracle One on One" book and the Oracle 8 and Oracle 10g R2
> Concepts manual. The second of the above quotes (from another book by
> Tom Kyte) seems to be in agreement with the article written by Svend
> Jensen on Jonathan Lewis's website.
>
> It makes one wonder... is there a correct answer?
>
> Charles Hooper
> IT Manager/Oracle DBA
> K&M Machine-Fabricating, Inc.- Hide quoted text -
>
> - Show quoted text -- Hide quoted text -
>
> - Show quoted text -
Yes, there is correct answer "the quote which I sent in my previous
mail". Apparenetly you have never used this feature. Once you use the
feature haze will disappear.
Received on Mon Jul 02 2007 - 09:08:48 CDT
