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Message Posted: Mon, 23 Aug 2004 @ 15:44:02 GMT
| Subj: | | Re: Different Explain for identical query with different users |
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| From: | | Victor Sokovin |
| | One thing that changed recently is that I added a multi-column statistic on the table that has the user qualification on it. The
statistics are collected on a combination of article numbers and the username, which is then specified in the where clause (both articles and the
username are specified in the where-part). The user with the 'correct' explain has no rows in this table. | |
It might help if you could show the exact SQL you are using. It sounds like you have a mix of "data" and "sessions" here. If user names
are just stored as data in a column (COL_USER_NAME) then queries with the COL_USER_NAME = 'some_value' clause may have different explain plans.
That happens often. If this 'some_value' is somehow derived from the logon user name by the application then it's just that, nothing very
special.
To test that logon as one generic user and check explain plans for differen user name values. If they are different look at the data
distribution for (article, user name) combinations. Different distributions may lead to different explains.
Does the above apply to your case?
Victor
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