What specific version of 11g down to patches applied? (opatch lsinventory)
What specific version of 12c on Exadata down to patches applied? (opatch
lsinventory)
Did you port the plan baselines/outln data to 12c?
We could simply start with the query and execution plan on 12c side to see what
it may be doing. We would also need a pfile created from the spfile to see what
parameters you have set on the database.
From: oracle-l-bounce@xxxxxxxxxxxxx <oracle-l-bounce@xxxxxxxxxxxxx> On Behalf
Of kunwar singh
Sent: Monday, August 12, 2019 11:13 PM
To: ORACLE-L <oracle-l@xxxxxxxxxxxxx>
Subject: Bad execution plan after migrating to exadata ( 12c) from non-exadata
(11g)
Hi Listers,
How to approach this? Looking for a approach in general when it comes to check
plan issues when migrating to exadata and not something to this query ( but
wont mind any insights into it either ;) )
Issue:
with outline data from 11g(in 12c exa DB)
- cost ~90k, fast, elapsed time about 15 ms.
- doing index range scan on a index on a 2GB table .
12c exadata
- cost ~6k , slower , elapsed time about 4 seconds.
- FTS on the 2GB table and from sql monitor report time is spent on reading it
only/processing the hash join on it.
- execution plan is having a view VW_NSO_1
Few details:
1. I have already gathered stats on all tables/indexes
2. Have gathered system statistics with 'EXADATA'
3. Don't have the access to source 11g DB . getting it will take some time.
Will post redacted version of the SQL & the execution plan ( if you prefer to
look at it ) as account is very strict about security.
--
Cheers,
Kunwar
