Re: Partitionining perfortmance degraded drastically after upgrading the database from Oracle 102.0.4 to Oracle

From: Lothar Flatz <>
Date: Fri, 09 Jan 2015 15:13:12 +0100
Message-ID: <>

Hi Ashoke,

your memory issue look kind of wierd and certainly not correct. It looks like the amount of memory used to be 12 GB in 1o and is now 6 GB. That is certainly not the idea. I usually advise people to set PGA and SGA manually.
(Not use memory target.) There are better people than me to answer the memory stuff however. I am no DBA.
I am performance specialist.
If you have an issue with the PGA your temp waits will have increased.

However it is very difficult to advise if we have no evidence at all. Ideally I would have a sql monitor from one of your slow queries and that would tell me everything.
Or as a minum send the top 5 wait events from AWR.



Am 09.01.15 um 14:58 schrieb Mandal, Ashoke:
> Greetings All,
> I have upgraded one of my 2TB databases with partitioned tables & indexes from Oracle to Oracle recently and experiencing severe poor query performance. The response time of the queries have increased by 20-25 times.
> Before the upgrade to 11g
> After the upgrade to 11g
> My understanding is that if I set SGA_TARGET and PGA_AGGREGATE_TARGET parameters to 0 then Oracle manages theses as per the MEMORY_TARGET parameter in 11g.
> Q. Is it true that the SGA can't grow more than 1GB since SGA_MAX_SIZE is still set to 1GB?
> Q2. Will the performance improve by setting SGA_TARGET to 4GB by default?
> Q3. Should I also set the PGA_AGGREGATE_TARGET to GB as it was prior the upgrade?
> Q4. Any known issue of partitioning performance impact after you upgrade a 10g database to 11g?
> Please let me know if you any suggestions to resolve this issue
> Appreciate your help in advance,
> Ashoke
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Received on Fri Jan 09 2015 - 15:13:12 CET

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