[dev] SQL updates (was Re: Redundant index in table mnemo_memos?)

[Duck]

On Tuesday 22 August 2006 07:46, Chuck Hagenbuch wrote:
> Looking at the code, most of the time we query on both ticket_id and
> ticket_owner; sometimes just on ticket_id. So does changing it to use:
> PRIMARY KEY (ticket_id, ticket_owner)  ... sound right?
>

Indexes should flow data logic. So in this case the  PRIMARY KEY (ticket_id, 
ticket_owner)  should be right. This will benefit even of a second database 
unique check. I will create the same index type for other tables without 
indexes.

And is really not a problem if we accessing only one part of index.  Mysql 
will use only the needed part. Since combined index in selection 
are “ungrouped” and taken separately. It will use all the indexes or their 
pars needed for the query.

Duck