Re: latch contention

Try using multiple LRU latches and an equal amount of DBWR's This way the LRU hash chains become smaller and thus the LRU latches will be held for
a smaller amount of time ... in 8i you could also split up your buffer cache into keep, default and
recycle pools each with their own dedicated LRU latches and DBWR's ...

Kurt.

"Alexey Ogol" <lesha_at_crgu.com> wrote in message news:9hc80g$2m36$1_at_pandora.alkar.net...
> > 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.
> I run 8.1.7 EE, and it seems that there's no DB_BLOCK_HASH_BUCKETS
> parameter.
> Adjusting db_block_buffers doesn't help too...
> What else can I do?
>
> > 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.
>
>
>
Received on Wed Jun 27 2001 - 04:21:51 CDT