Re: Temporary segments in temporary tablespaces

  • From: "Jeffrey Beckstrom" <JBECKSTROM@xxxxxxxxx>
  • To: <danp@xxxxxxxxxxxxx>,<oracle-l@xxxxxxxxxxxxx>
  • Date: Fri, 13 Aug 2010 10:22:51 -0400

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@xxxxxxxxxxxxx> 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
an application that comes in through some OCI libraries and opens a 
connection but doesn't close it as the overhead of making the
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 

Any insights would be greatly appreciated.

Dan Peacock
Auto-wares, Inc.
Secretary of the West Michigan Oracle Users Group

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