On 1/2/07, Matt S Trout <[EMAIL PROTECTED]> wrote:

On 31 Dec 2006, at 09:25, Matt LeBlanc wrote:

>
> This would be because MySQL tends to suck the more you join. In most
> other databases, joins tend to be much quicker with slower subqueries.

Actually, databases with a decent optimiser will tend to unroll
subqueries and the execution plan will be equivalent to the join.
Certainly Pg's will do this in many cases.


Yes, if the optimizer is smart enough. Of course, then I would have to
input SQL to my SQL wrapper. ;)

More pertinently, I suspect the join cond you want isn't currently
achievable with DBIx::Class whereas aristotle's approach is, so I'd
suggest going with his approach and if it turns out to be a major
performance issue perhaps we can discuss what changes need to be made
and how the syntax would need to be extended in order to support yours?


Last I checked, it isn't. I have a hacked up version of DBIx::Class
locally that allows such niceties as dynamic join conditions and
quoted order by clauses with direction (don't know if this is
currently available but it wasn't last I checked).

--
Matt S Trout, Technical Director, Shadowcat Systems Ltd.
Offering custom development, consultancy and support contracts for
Catalyst,
DBIx::Class and BAST. Contact mst (at) shadowcatsystems.co.uk for
details.
+ Help us build a better perl ORM: http://dbix-
class.shadowcatsystems.co.uk/ +


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