RE: AUTO ALLOCATE PERFORMANCE

  • From: "Powell, Mark D" <mark.powell@xxxxxxx>
  • To: <oracle-l@xxxxxxxxxxxxx>
  • Date: Thu, 29 Mar 2007 13:29:18 -0400

If the old tablespace was using dictionary management then depending on
the table/index storage parameters in use and the existing free space
fragmentation status of the target tablespace switching to using a
tablespace built as auto-allocate could greatly reduce the number of
extent allocation events that took place.  Depending on other system
activity that uses the single database 'ST' lock this change may have
reduced contention on the 'ST' lock.  Less contention and less extent
allocations would equal better performance though 20 minutes off of 90
does seem to require some other factors to be involved.
 
Is this a parallel or direct load?  Is ASSM also now in use?  
 
You mentioned unindexed queries, what do these have to do with the load?
Is the data being inserted built from queries or is this just a comment
on how the application runs?
 
-- Mark D Powell -- 
Phone (313) 592-5148 
 


________________________________

        From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Wolfson Larry -
lwolfs
        Sent: Wednesday, March 28, 2007 12:26 PM
        To: oracle-l@xxxxxxxxxxxxx
        Subject: AUTO ALLOCATE PERFORMANCE
        
        
        Hey guys,  I've got a vendor claiming his batch load runs in 70
minutes instead of 90 on his test system when he switched to
AUTOALLOCATE.
         
          Can't say I've seen a lot of info on performance improvements
with AUTOALLOCATE.
         
            Anybody have a take on this?  He hasn't given me his code
yet. All I've seen is FTS because all his SELECTs use UPPER everywhere
and never use any indexes.  His biggest table has 26 of them and I'm
gonna see if he really uses any.  Sorry nothing to do with AA question.
         
         
            TIA
            Larry
         
         
            
        
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