This week's book giveaway is in the OCMJEA forum.
We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line!
See this thread for details.
The moose likes JDBC and the fly likes Different Execution Plans for 2 instances of the same database.. Why??.. Help me out Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login


Win a copy of OCM Java EE 6 Enterprise Architect Exam Guide this week in the OCMJEA forum!
JavaRanch » Java Forums » Databases » JDBC
Bookmark "Different Execution Plans for 2 instances of the same database.. Why??.. Help me out" Watch "Different Execution Plans for 2 instances of the same database.. Why??.. Help me out" New topic
Author

Different Execution Plans for 2 instances of the same database.. Why??.. Help me out

Sajee Joseph
Ranch Hand

Joined: Jan 17, 2001
Posts: 200
Hello all,
I have a problem with Execution Plan
Here I have a SQL query, which I am running on 2 databases. The 2 databases are same snapshots but at different locations. The local database
( database which is on local server ) is giving different SQL Execution planand the remote database is giving different execution plan.
All the init.ora parameters are same. Both the databases have same tables and same number of records every thing is same. Even then, why it is giving different Execution plans.
The only major difference it showing is, at local database, at one point/level the execution plan is using the "HASH JOIN", whereas in remote database at the same point/level, the execution plan it is using "NESTED LOOPS". Why it so ?
Please Help me out.
Regards,
Saj
SJ Adnams
Ranch Hand

Joined: Sep 28, 2001
Posts: 925
table has not been analysed i guess?
Loren Rosen
Ranch Hand

Joined: Feb 12, 2003
Posts: 156
different indexes
instances were analyzed at different times (or one not at all)
different Oracle versions
 
I agree. Here's the link: http://aspose.com/file-tools
 
subject: Different Execution Plans for 2 instances of the same database.. Why??.. Help me out