On Mon, Oct 16, 2006 at 07:06:58PM +0100, Tony Bowden wrote:
>
> After investigating a set of particularly problematic queries that were
> each taking 40 minutes(!) to run we noticed a very peculiar clause in
> the query, which basically boils down to a select on
>
> Tickets LEFT JOIN TicketCustomFieldValues
> ON TicketCustomFieldValues.CustomField = '1'
> OR TicketCustomFieldValues.Ticket = Tickets.id
>
> Unless I'm missing something important about how this should work, this
> should surely be an AND, not an OR. And, indeed, replacing the OR with
> an AND and running the query by hand gets back the correct results in a
> fraction of a second.
That sure doesn't look right, but 3.2.2 was a _long_ time ago. 3.4
entirely reimplemented the custom fields searching, and 3.6 further
improved queries on customfields.
>
> This appears to have happened after we upgraded mysql.
From what to what? We've seen pathalogically bad query optimization on
5.0. But still, that query above just doesn't look right.
-j
_______________________________________________
http://lists.bestpractical.com/cgi-bin/mailman/listinfo/rt-users
Community help: http://wiki.bestpractical.com
Commercial support: [EMAIL PROTECTED]
Discover RT's hidden secrets with RT Essentials from O'Reilly Media.
Buy a copy at http://rtbook.bestpractical.com
