 | | | Subject: RE: v$session_longops | Subject: RE: v$session_longops 2007-10-03 - By Tanel Poder
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Hi,
The session longops array is split into multiple parts each having its own
freelist and latch.
Operations on each array are protected by separate "longop free list parent"
latches ( controlled by _num_longop_child_latches parameter ).
The max number of longop slots is "hardcoded" into Oracle using ksulomx_
variable:
SQL> oradebug dumpvar sga ksulomx_
ub4 ksulomx_ [380007E78, 380007E7C) = 000001F4 <<<--- 0x1F4 is 500 in
decimal
The longop array used by a session is probably determined by a MOD function
on SID or Oracle PID, so a session does not see all free slots, thus the
"oldest" longop slot doesn't necessarily get reused first.
--
Regards,
Tanel Poder
http://blog.tanelpoder.com
> -- --Original Message-- --
> From: oracle-l-bounce@(protected)
> [mailto:oracle-l-bounce@(protected)] On Behalf Of Gints Plivna
> Sent: Wednesday, October 03, 2007 15:09
> To: info@(protected)
> Cc: oracle-l@(protected)
> Subject: Re: v$session_longops
>
> Jonathan Lewis has written an answer here about the maximum
> number of entries:
> http://www.mcse.ms/message1574958.html
> He said "The number of slots
> in v$session_longops for 9.2.0.6 seems to be the lower of 500
> and 2 x the sessions parameter."
> Of course you can quite easily test whether it is relevant
> also for 10g for example.
>
> However I cannot say anything about the precise algorithm of
> reuse of entries.
--
http://www.freelists.org/webpage/oracle-l
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