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Performance issues after a migration

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2,708

Hey all, We have recently migrated all our SAP systems from one datacenter to a new one, as well moved our systems from rack servers to VMware / Blades.  Since then, we has been hit with some major performance bottlenecks.

The issue we seem to be seeing is with the database...

Here is the situation:

1. When we run a query or update in ECC Production (that use to take seconds in the old datacenter on the old server) - and now ends up taking i.e. 6

min to run.

2. However, when we run the same query in QA - and the report runs instantly (within seconds).

Both Prod and QAS are copies, both running on the same VM, same memory,etc. However, from what we see, production takes so incredibly long

to do what it use to in seconds... while QAS seems to run fine.

During these periods, we also see a lot of activity on the disks in production, and none in QAS. This leads us to believe the in production,

the oracle database is doing sequential reads nonstop.. while in QA - the data gets buffered as it should.

Does anyone know if:

1. This makes any sense?

2. What parameters should we look at that might cause this type of behavior... specifically, what are the parameters that would cause a

system to go to disk every time for data (vs. getting it from the buffers).

Any help resolving this is greatly appreciated

Richard

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former_member184473
Active Contributor
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Hello Richard,

After the migration, have you update the statistics (note 588668)?

       brconnect -u / -c -f stats -t oradict_stats

       brconnect -u / -c -f stats -t system_stats

       brconnect -u / -c -f stats -t all

Are the parameters correctly set (note 1171650)?

Are you using the latest patchset (note 1503709)?

Regards,

Eduardo Rezende

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Hi Eduardo,

Thank you,  yes, we ran stats, prams are correct, and we are on the latest patch set.

However, you made us question if perhaps stats were run correctly...  We plan on running them again after hours...   thank you again, and keeping my figures crossed...

R