| Explain Plan [message #271181] |
Sun, 30 September 2007 09:52  |
navkrish
Messages: 189
Registered: May 2006
Location: NJ,USA
|
Senior Member |
|
|
All,
There are two environments E1 and E2. I fired a query involving 12 tables in both the environment. I got different explain plan. Difference was in E2, two tables doesn’t uses index and there appears to be full table scan.
Query is running fast in E1 than in E2. I compared the constraint and indexes on both environment and didn’t find any difference.
I'm confused why optimizer it not picking the indexes in E2 but it does in E1.
Your suggestions would be highly appreciated.
Thanks,
Naveen
[Updated on: Sun, 30 September 2007 09:54] Report message to a moderator |
|
|
|
|
|
|
|
|
|
|
|
| Re: Explain Plan [message #271518 is a reply to message #271184] |
Mon, 01 October 2007 16:54  |
OracleDisected
Messages: 25
Registered: September 2007
Location: Mexico
|
Junior Member |
|
|
Both environments are running under Cost Based Optimizer?
... in order to use statistics
If data (row count level) is substantially different, then it will affect statistics (even if they are up-to-date on both environments).
If row count for every table is the same, or scaled by an almost equal factor, there is no impact. Just check if your statistics are up-to-date.
Regards
Ignacio
[Edit MC: url to poster blog removed. We don't care about your blog in this post. If you have an answer on your site, post a link to this answer. If you don't, post your blog url in Marketplace]
[Updated on: Thu, 11 October 2007 12:40] by Moderator Report message to a moderator |
|
|
|
] 
Blog
Search
Help
Members
Register
Login
Home
