Re: buffer busy waits

From: K Gopalakrishnan <kaygopal_at_gmail.com>
Date: Sat, 30 Jul 2005 04:27:13 +0530
Message-ID: <3b0f44a105072915571e0609ad@mail.gmail.com>

Allen:

You can findout what are the _exact_ system calls causing the buffer busy waits using the following SQL. This will give a fair idea about the operations causing the bbw and you can narrow down the cause/action from the result.

SELECT WH.KCBWHDES "MODULE",SW.WHY0 "CALLS",SW.WHY2 "WAITS", SW.OTHER_WAIT "CAUSED WAITS"
FROM x$kcbwh WH, x$kcbsw SW
WHERE WH.indx = SW.indx
AND SW.OTHER_WAIT > 0
ORDER BY SW.OTHER_WAIT; Basically by reducing the concurrency at block level, you can easily combat the BBWs.

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Best Regards,
K Gopalakrishnan
Co-Author: Oracle Wait Interface, Oracle Press 2004 http://www.amazon.com/exec/obidos/tg/detail/-/007222729X/
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http://www.freelists.org/webpage/oracle-l Received on Fri Jul 29 2005 - 17:59:13 CDT