At 13:35 18/11/99 +0100, Jochen Wiedmann wrote:
>I have a table similar to the following:
>
> start INTEGER
> end INTEGER
>
>where start <= end are arbitrary ranges.
>
>
>Does anyone have recommendations of how to choose an index
>that allows me to select those records that include a certain
>number? In other words, I like to optimize the query
>
> SELECT * FROM mytable WHERE start <= mynumber AND
> end >= mynumber;
>
>
>Thanks,
>
>Jochen
<snip>
This is a bit OT. but its so easy.....
Have 2 indices; one of each! -
ALTER TABLE tablename ADD INDEX tablename_se (start, end);
ALTER TABLE tablename ADD INDEX tablename_es (end, start);
Then the optimizer can choose which is the best to use.
Colin
