Re: latch contention

Your advice is sound, but in this case the original problem specifies the latch

    cache buffers chains,
not the

    cache buffers LRU chain

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koert54 wrote in message ...


>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.

>>

>>

>>

>

>