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Re: Row cache lock wait issue in RAC

From: Radoulov, Dimitre <cichomitiko_at_gmail.com>
Date: Wed, 31 May 2006 22:54:40 +0200
Message-ID: <01bf01c684f4$709bc060$2308310a@MPILA9>

> I am stress testing an application that performs massive inserts (logs
> tons of data) into Oracle tables using direct path insert. Multiple>
> tables are used to provide scalability (each log source inserts into a
> dedicated table). This application uses direct path inserts and bypasses
> the cache so I can see that it also scales in RAC (10g RAC, 6 nodes).
>
> BUT increasing the number of log sources I have now started to see the
> following bottleneck: row cache wait (on dc_tablespace_quotas), for
> example from a 10046 trace:
> ---------------------------
> WAIT #19: nam='row cache lock' ela= 2888862 cache id=5 mode=0 request=5
> obj#=76647 tim=1122164147766228
> WAIT #19: nam='row cache lock' ela= 2824967 cache id=5 mode=0 request=5
> obj#=76647 tim=1122164150591291
>
> It looks to me as row cache lock contention between direct path inserts,
> probably made worse by rac/GES. (Note also that I don't enforce
> tablespace quotas (the application owner has unlimited tablespace).
>
> Any ideas on how to tune this?

Just an idea: why don't you try to remove user's unlimited quota privilege and assign a specific quota?

Regards
Dimitre

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Received on Wed May 31 2006 - 15:54:40 CDT

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