On Tue, Jan 22, 2002 at 10:19:46AM +0100, Roger Baklund wrote: > > Just to make it clear: this is the primary key, and all four parts > of the index are needed to identify the row. Most of the time I use > the three first parts, sometimes I use all four parts, and sometimes > I use only the first two parts. > > My question was: is it better to have the part with most distinct > values first, or is it better to have the part with very few > distinct values first, when _all_ queries _always_ use both parts?
It is better, yes. How much better, I cannot say without testing. > I believe the answer to this depends on how the index is stored and > handled internally by mysql, and as I do not have this knowledge, I > asked the list... I understand now. Jeremy -- Jeremy D. Zawodny, <[EMAIL PROTECTED]> Technical Yahoo - Yahoo Finance Desk: (408) 349-7878 Fax: (408) 349-5454 Cell: (408) 685-5936 MySQL 3.23.41-max: up 20 days, processed 479,662,744 queries (266/sec. avg) --------------------------------------------------------------------- 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
