[EMAIL PROTECTED] wrote:
> Ok, I will be the first to say that I am learning about indexes, however > it is my understanding that if I have a database with MANY rows and I > wish my queries to be faster I should index my database. With that being > said, I have 2 tables in my database that are being queried with a > single query using a UNION these 2 tables combined are about 9 Million > records (yes I said million). > > My query which is below takes about 1 minute to run, now some people > would say that this isn't long, however when the 2 tables were sub 5 > million it only took a matter of about 20 seconds to run, so I figure I > need an index. So I have created an index called "Main" within both > tables and added 6 columns to that index, most of the columns that are > used in my query. > > Sorry for the long background, but here is the problem, my query DID NOT > speed up at all. It still takes right at 1 minute per query, so indexing > didn't buy me anything as far as I can tell. > > Can someone tell me how the indexes are supposed to be done ( to ensure > that I did it correctly) and tell me if they think that it should have > sped up or if there is a more efficient way to do my query. > You should debug (read = investigate) your query using EXPLAIN SELECT statement. Read http://dev.mysql.com/doc/mysql/en/EXPLAIN.html and perhaps http://dev.mysql.com/doc/mysql/en/Query_Speed.html -- For technical support contracts, goto https://order.mysql.com/?ref=ensita This email is sponsored by Ensita.net http://www.ensita.net/ __ ___ ___ ____ __ / |/ /_ __/ __/ __ \/ / Egor Egorov / /|_/ / // /\ \/ /_/ / /__ [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]
