Hello.
>I am not sure if the key is only built on a single col ( I added Use SHOW INDEX or SHOW CREATE TABLE statements. See: http://dev.mysql.com/doc/mysql/en/show-index.html http://dev.mysql.com/doc/mysql/en/show-create-table.html I think you should send your query, the output of EXPLAIN statement and the definitions of your tables which are used by query. Ginger Cheng <[EMAIL PROTECTED]> wrote: > Hello, MySQL gurus, > I have a non-unique key of 2 columns, the 1st is a varchar(15), > 2nd is a int(10) unsigned. But when I 'explain' a query that uses this > key, the key_len is only 15 with the key name shown up in the 'key' > column of this table correctly though. According to the manual, that > means how many columns of a key is accually used in the query. So the > query is only using the 1st column of my key although it could not be > efficient without using the 2nd column. > I am not sure if the key is only built on a single col ( I added > the index as 'ALTER TABLE a ADD INDEX (f, s)') or it is the MySQL > optimizer that decides it will only use the 1st column of the key. Is > there any way to check and get it right? > Thank you all for help > -- For technical support contracts, goto https://order.mysql.com/?ref=ensita This email is sponsored by Ensita.NET http://www.ensita.net/ __ ___ ___ ____ __ / |/ /_ __/ __/ __ \/ / Gleb Paharenko / /|_/ / // /\ \/ /_/ / /__ [EMAIL PROTECTED] /_/ /_/\_, /___/\___\_\___/ MySQL AB / Ensita.NET <___/ www.mysql.com -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
