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Re: MIN on an indexed field too slow
Posted by: Apachez
Date: March 01, 2006 03:25PM

In your min example you use "WHERE col2 = xxx AND col1 = xxx" but your index is (col1, col2) and not (col2, col1).

Try to rewrite your query so it is something like:

SELECT MIN(recordNumber) FROM oaa_account WHERE recordNumber > 66728314 AND recordType = 0;

Also run an EXPLAIN SELECT on both your previous min query and the one I wrote above and paste the results in this forumthread.

The number of rows examined might be because you have that many rows which has recordNumber > 66728314.

Try a:

SELECT COUNT(*) FROM oaa_account WHERE recordNumber > 66728314;

vs your previous query (but modified for count()):

SELECT COUNT(*) FROM oaa_account WHERE recordType = 0 AND recordNumber
> 66728314;

along with EXPLAIN SELECT on both above queries.

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