Re: how 8.1.7.4 calculates the # of 'library cache' latch children ?

On 25 Nov 2003 07:12:32 -0800, alberto.dellera_at_bigfoot.com (Alberto Dell'Era) wrote:

>Does anybody know how the number of 'library cache' latches are
>determined by the 8.1.7.4 kernel ?
>
>Yesterday we had 11 children and today we have 17 of them, after
>(1) upping the shared_pool dimension from 150M to 400M
>(2) increasing cpu_count from 10 to 14
>
>Which one (or other) caused the birth of the 6=17-11 children ?
>
>This is very relevant to us since a f#@%ing third-party applications
>overparses millions of statements (no bind variables, parse
>once-execute once ...) and, until they solve the problem (in 2020AD I
>guess), i would like to limit the damage by at least increasing that
>number.
>
>Thanks
>Alberto

The number of latches is determined by the size of the shared pool. There should be no need to increase the cpu_count, or you must be in want of to create havoc. Oracle automatically determines the number of cpu's correctly for most platforms, and setting an artificial number may have adverse results.
To reduce the number of parses you should set cursor_sharing to force. This can be done on session, system and instance level.

--
Sybrand Bakker, Senior Oracle DBA