Re: log buffer space

KG,

I got the direct mail much quicker than the list mail - but I'll just echo the doubt I raised in the original.

If you use 10046 level 8 to watch for log writer writes, I would expect you to see writes that could be of an almost arbitrary size.

Assume a 3MB log buffer - we 'know' that Oracle triggers on 1MB: but what if the system is busy when a write is triggered and the users are generating lots of work ?

LGWR writes 1MB - and in that time interval the users fill the other 2MB of the log buffer. The next write that LGWR does is 2MB.

You could even argue that if the largest write you regularly see is 2/3 of the log buffer size, then the trigger is probably 1/3 of the log buffer size.

Regards

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

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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> Sent: 17 March 2003 17:42

> Jonathan:
>
> I have just sent a mail which has the test statistics.
> I would appreciate your comments on that..
>
> Alternatively, people who are curious may want to
> test the log writer writing habits using the
> event 10046^8.
>
> KG
>
>
> Best Regards,
> K Gopalakrishnan
>

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Author: Jonathan Lewis
  INET: jonathan_at_jlcomp.demon.co.uk

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