Hi, I have some compound primary keys, all integer fields (a,b,c,d). In one table we have by mistake made the key (b,a,c,d). We allways use at least field a and field b in all lookups, and it seems to be working, but I wanted to ask: does it matter? Should we change the 'wrong' primary key to (a,b,c,d)? (Will mysql perform better/faster?)
Also, I wonder what is the best order for my primary keys: a int This is the 'main' id, very many distinct values b tinyint This is a source code, possible values are 1 or 2 c smallint Some counter d tinyint Another counter or b tinyint This is a source code, possible values are 1 or 2 a int This is the 'main' id, very many distinct values c smallint Some counter d tinyint Another counter Which will perform faster, when all lookups use both a and b? -- Roger --------------------------------------------------------------------- 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
