Re: Row cache locks on INSERTs with a sequence

If the wait times on the latch were significant, I think I'd check that the inserts were high volume inserts into tables with a very small extent sizes and lots of indexes, also with very small extents.

I wouldn't have thought it was anything to do with sequences.

Regards

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

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____England______January 21/23

The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html

-----Original Message-----
To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com> Date: 20 December 2002 16:56

>We are continually seeing sessions hanging on row cache locks, which
in
>turn appear to be on dc_segments:
>
> SID EVENT P1TEXT P1 P2TEXT P2 P3TEXT P3
>----- ----------------- ---------- -- -------- -- --------- ----
> 29 row cache lock cache id 13 mode 0 request 5
> 105 row cache lock cache id 13 mode 0 request 5
>
>The offending SQL statement is an INSERT of the following form:
>
>INSERT INTO TABLE (A,B,C,D...) VALUES (:b1, :b2, :b3,
SEQUENCE.NEXTVAL,..)
>
>The sequence in question has it's cache value set to the default of
20.
>
>The developers keep insisting that it's a shared pool issue. I've
>researched Metalink and not come up with a whole lot. I've ran
>statspack and it has rendered advice with respect to the fact that a
lot
>of new sequence values are being acquired, therefore the sequence
cache size
>needs examination.
>

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: Jonathan Lewis
  INET: jonathan_at_jlcomp.demon.co.uk

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