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Re: two column int index not used correctly
Posted by: Jørgen Løland
Date: June 15, 2011 11:30PM

Hi Ming,

Like I told Alexander, it's very difficult to resolve range queries with a WHERE clause like you two have...

column_a cmp constant1 AND column_b cmp constant2
(where cmp is any of <, >, <=, >=, between)

...in an efficient way if many or even most rows in the table have different column_a values. You might want to look into that because I don't think it will scale to a great number of rows.

Hope this helps,
Jørgen Løland
Software Engineer, MySQL, Oracle
jorgenloland.blogspot.com



Edited 1 time(s). Last edit at 06/15/2011 11:30PM by Jorgen Loland.

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