Re: Temporary segments in temporary tablespaces
Date: Fri, 13 Aug 2010 10:56:42 -0400
Message-ID: <4C655D2A.406_at_autowares.com>
Good question. I'll try asking the developers but I suspect I'll get a blank stare. They send their SQL into the processing engine and stuff comes back out. The guy who wrote the OCI interface may not be much help either. I'll check to see how current cursors fluctuates during the day and see if this persistent connection isn't closing things right.
Dan
On 08/13/2010 10:22 AM, Jeffrey Beckstrom wrote:
> Might it be that you are leaving the cursor open and thus Oracle is
> not cleaning it up?
> Jeffrey Beckstrom
> Database Administrator
> Greater Cleveland Regional Transit Authority
> 1240 W. 6th Street
> Cleveland, Ohio 44113
>
> >>> Dan Peacock <danp_at_autowares.com> 8/13/10 8:31 AM >>>
> Good Morning List!
>
> I've been working on a "problem" with my developers that I'm stumped by
> and I'm hoping the collective can shed some light on it for me. We have
> an application that comes in through some OCI libraries and opens a
> connection but doesn't close it as the overhead of making the connection
> is too steep for the scanner application that uses the library. The
> consequence of this is, as time wears on it seems that the temporary
> sort segments accumulate for the connected user to the point where
> there's nothing left for "real" work and applications start crashing
> with "unable to extend TEMP" (other applications use these same
> libraries and can run some pretty hefty queries). My understanding was
> that SMON would come through and clean up temporary segments that were
> no longer needed but we did some testing and don't think this is the
> case for an open connection.
>
> Here's what we did:
>
> 1) We have a SQL statement that we know puts stuff out into the TEMP
> tablespace due to sorting. Approximately 24mb of sort space is used by
> this statement.
> 2) We ran the statement, issued a commit to start a new "transaction".
> 3) Ran the statement again and are now consuming 48mb of TEMP space.
> 4) We waited for over an hour and the amount of space never went down.
> 5) Thinking it was just allocated to us and would be reused we tried it
> again and are now sitting at 72mb of TEMP space
>
> So, my question is, short of closing and reopening the connection, what
> can we do to force these segments to release and get reused. We've
> already resized the PGA and that helped some, but it only delays the
> inevitable.
>
> Any insights would be greatly appreciated.
>
> Dan Peacock
> Auto-wares, Inc.
> Secretary of the West Michigan Oracle Users Group
> --
> http://www.freelists.org/webpage/oracle-l
>
>
-- http://www.freelists.org/webpage/oracle-lReceived on Fri Aug 13 2010 - 09:56:42 CDT