Dan, thanks for your reply. When I changed the table definition to use the single index and the multi-index I reloaded the data from scratch each time. (I did the trials many times from scratch just to be sure and I do get consistent results)
I also just did an optimize table as you suggest on the single index just to be sure and I get the same results. John On Thu, Nov 21, 2002 at 05:22:05PM -0600, Dan Nelson wrote: > In the last episode (Nov 21), [EMAIL PROTECTED] said: > > Adding an irrelevant second column to an index instead of just a > > single column index gives an incredible speedup and I don't know why! > > If you then remove the index, is it still fast? Maybe you are just > seeing the results of mysql rebuilding the state key. When you modify > an index, I believe mysql ends up rebuilding all indexes on that table. > "optimize table mytable" would probably have given you the same speed > boost. > > -- > Dan Nelson > [EMAIL PROTECTED] --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
