[Dbmail] mysql redundant indexes

[Blake Mitchell]

I've noticed that in several places, there are redundant indexes created 
on the same column. For example, in sql/mysql/create_tables_innoDB.mysql 
you have this:

CREATE TABLE tmpmessage (
<snip>
      PRIMARY KEY (message_idnr),
      KEY message_idnr (message_idnr),
      UNIQUE message_idnr_2 (message_idnr)
) TYPE = InnoDB;

Here we have three indexes created on exactly the same column. Not only 
are primary keys indexes, but they must be unique. So the single primary 
key would suffice for this table.

For more info on this subject, see: 
http://forums.devshed.com/showthread.php?threadid=38886