In MySQL 4.1.11, if you create two temporary tables with non-unique indices as part of the CREATE TEMPORARY TABLE statement, then insert several hundred (or thousand) rows, a subsequent SELECT using a JOIN between the two tables is substantially slower than if you create the indices after inserting the rows into the temporary tables. When I run a SHOW INDEX for these tables, the only difference is the Cardinality field, where it is NULL if the index was created prior to any inserts and is a number if the index was created after the inserts.
Why is it that adding an index before or after the addition of data makes a difference on SELECT performance? Allan Miller -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
