| Query perfomance [message #392598] |
Wed, 18 March 2009 10:30  |
gkrishn
Messages: 506
Registered: December 2005
Location: Putty a dark screen
|
Senior Member |
|
|
I am today troubleshooting a query perfomance problem.
Runs good in UAT but not in PROD. i have verified the execution plan and it goes for a FULL TABLESCAN for Table1 & Table with hight cost, which is not the case in UAT.
BUT When i checked the activity through Oracle EM ,it shows high activity (DB FILE SEQUENTIAL READ) for another table , Table3 .
Any idea what is the catch here.Should i consider the first case or second.Any tips are highly appreciated.
|
|
|
|
|
|
| Re: Query perfomance [message #392603 is a reply to message #392598] |
Wed, 18 March 2009 10:46  |
gkrishn
Messages: 506
Registered: December 2005
Location: Putty a dark screen
|
Senior Member |
|
|
we have weekly stats collection and must be through DBMS_STATS .
i have compared NUM_ROWS and count(*) are almost similar
|
|
|
|
|
|
| Re: Query perfomance [message #392610 is a reply to message #392598] |
Wed, 18 March 2009 11:09 |
gkrishn
Messages: 506
Registered: December 2005
Location: Putty a dark screen
|
Senior Member |
|
|
both the environment use DBMS_STATS with same params.We use same shell script in both environments.
And about the SQL, yes that must be the case.
but still i am wondering why its going for DB FILE SEQUENTIAL READ for table3 .This is the high activity it shows in Oracle EM.
|
|
|
|
| Re: Query perfomance [message #392611 is a reply to message #392610] |
Wed, 18 March 2009 11:15 |
 |
Mahesh Rajendran
Messages: 10707
Registered: March 2002
Location: oracleDocoVille
|
Senior Member
Account Moderator |
|
|
>>but still i am wondering why its going for DB FILE SEQUENTIAL READ for table3
So are we.
You have not posted anything useful, but just explained your observations.
No SQL, No plan, no stats information, no trace and no nothing.
Good luck!.
|
|
|
|
] 
Blog
Search
Help
Members
Register
Login
Home
