Re: 8.1.7 cache buffer chains contention

The reported problem was 'cache buffers chains' latching, with one specific block being responsible for most of the lost time. This can only arise if (a) the latch is acquired too frequently for that buffer, or (b) the latch is held to long for that buffer.

I doubt if LRU latching comes into it at all - although if the database write rate was too ferocious, then we would perhaps expect to see other waits appearing in association with this latch wait.

--
Jonathan Lewis
http://www.jlcomp.demon.co.uk

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Practical Oracle 8i: Building Efficient Databases

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Nuno Souto wrote in message <3b8b7406.4484189_at_news>...


>On Tue, 28 Aug 2001 07:58:20 +0100, "Jonathan Lewis"

><jonathan_at_jlcomp.demon.co.uk> wrote:

>

>>

>>I've had a couple of thoughts about your latching

>>problem, and changes to the way Oracle may be

>>working.

>>

>

>Do you think he should be using a lot more LRU latches?

>(> 300000 buffers for only 30 of them, with probably a CPU farm

>sitting in there too, there could be a problem if there is lots of

>concurrent access to same table/index)

>

>

>Cheers

>Nuno Souto

>nsouto_at_optushome.com.au.nospam