Re: Cache buffer chains (kslbegin)

From: Alex Gorbachev <gorbyx_at_gmail.com>
Date: Mon, 24 Apr 2006 20:57:01 +0200
Message-ID: <c2213f680604241157t3c424583s7df15811186c82cf@mail.gmail.com>

Stephen,

In Statspack report you might find useful section "Top 5 Buf. Busy Waits per Segment" as well as "Tablespace/File IO Stats" (Buffer Waits column). Types of the blocks you can find in the "Buffer wait Statistics" section of a Statspack report.

You can check which sessions are responsible for those waits quering V$SESSION_EVENT if sessions are connected for relatively long time. You can than enable 10046 trace for those sessions and see reason code as well as problem statements. Or you can try to sample V$SESSION_WAIT as suggested already.

Better yet, I would tackle it from another point of view asking the question - which sessions experiencing performance problems. Perhaps, those sessions are not suffering from excessive "buffer busy waits".

Regards,
Alex

2006/4/24, Stephen Anderson <st.anderson_at_gmail.com>:

> Hello,
> I have a 10 minute statspack report from a busy time period, and have seen
> that buffer busy waits were the highest wait events. Would I be correct to
> then look at the Latch Miss Source at the largest sleeps? I have the
> following information there:

--
Best regards,
Alex Gorbachev
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Received on Mon Apr 24 2006 - 13:57:01 CDT