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Re: latch contention

From: George Barbour <george.barbour_at_gecm.com>
Date: Wed, 27 Jun 2001 10:08:40 +0100
Message-ID: <3b39a060$1@pull.gecm.com>

I'am always kinda wary of increasing DB_BLOCK_BUFFERS, as a universal answer to everthing.
I have seen my buffer_cache hit ratio going down to -0.8%. (Yes that is a minus sign, Yes that is a percentage ) and increasing the DB_BLOCK_BUFFERS did nothing.

George Barbour.

"giorgio.sorbara @ sorcius.com" <giorgio_at_yeahright.com> wrote in message news:9hc6f7$7iq$1_at_news.mclink.it...
>
> from metalink...
>
> Cache buffers chains latch:
> This latch is needed when user processes try to scan
> the SGA for database cache buffers.
> This latch is related to DB_BLOCK_HASH_BUCKETS (undocumented in
> Oracle7) which is related to db_block_buffers. It can be tuned by
> adjusting DB_BLOCK_BUFFERS.
>
> Cache buffers LRU chain latch:
> This latch is needed when user processes try to scan
> the LRU (least recently used) chain containing all the dirty blocks
> in the buffer cache.
> Cache buffers LRU chain latch:
> Increasing the parameters DB_BLOCK_BUFFERS and DB_BLOCK_WRITE_BATCH
> (undocumented in Oracle7) will reduce waits on this kind of latches.
>
> HTH,
> G
>
> "Alexey Ogol" <lesha_at_crgu.com> wrote in message
> news:9hc1k3$247n$1_at_pandora.alkar.net...
> > Hi,
> >
> > I run UTLBSTAT/UTLESTAT scripts, and I realize that there's a 'cache
 buffer
> > chains' latch contention in the database. How can I eliminate this
 problem?
> >
> > Thanks in advance,
> > Alexey
> >
> >
>
>
Received on Wed Jun 27 2001 - 04:08:40 CDT

Original text of this message

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