A composite index on both columns may be used by queries involving
either both columns, or the first column in the index.
http://dev.mysql.com/doc/refman/5.0/en/multiple-column-indexes.html
So, an index on (receiver_id, sender_id) may be used by predicates on
both columns or receiver_id
3:50 AM
To: Ananda Kumar
Cc: James Tu; MySQL List
Subject: Re: index, unique index question
A composite index on both columns may be used by queries involving
either both columns, or the first column in the index.
http://dev.mysql.com/doc/refman/5.0/en/multiple-column-indexes.html
So, an index
questions? Check the forum!
http://www.databasedevelopmentforum.com
-Noah
-Original Message-
From: Kristian Myllymäki [mailto:[EMAIL PROTECTED]
Sent: Tuesday, August 14, 2007 3:50 AM
To: Ananda Kumar
Cc: James Tu; MySQL List
Subject: Re: index, unique index question
A composite index on both
-
From: Kristian Myllymäki [mailto:[EMAIL PROTECTED]
Sent: Tuesday, August 14, 2007 3:50 AM
To: Ananda Kumar
Cc: James Tu; MySQL List
Subject: Re: index, unique index question
A composite index on both columns may be used by queries involving
either both columns, or the first column
Hi James,
Since your queries have both receiver_id and sender_id in the where
condition and u want this to be unique, just create one combined unique
index on both these columns.
Do this at db level will give you much better options, performance, rather
than doing at code level, which might
