maria-developers team mailing list archive

[Sergey Petrunya <psergey@xxxxxxxxxxxx>]

On Tue, May 25, 2010 at 11:00:02AM +1000, Arjen Lentz wrote:
> Hi Sergey
>
> On 25/05/2010, at 6:59 AM, worklog-noreply@xxxxxxxxxxxx wrote:
>> TASK...........: Push conditions down into non-mergeable VIEWs when  
>> possible
>> TASK ID........: 119 (http://askmonty.org/worklog/?tid=119)
>
>
> Will this have any effect on a VIEW containing a UNION?
>

This particular task won't, as we're looking to limit the scope of the WL, and
UNIONs are an easy target.

It is possible to push a condition inside UNION (as long as it's not UNION ...
ORDER BY), i.e. 

  (SELECT foo UNION SELECT bar) HAVING x  -->
  
  (SELECT foo HAVING x) UNION (SELECT bar HAVING h)

so we could add support for UNIONs after MWL#119 is complete. 

Arjen, do you mention UNIONs as something that's technically possible to
handle, or you're saying that there are cases with UNIONs of practical
importance?

BR
 Sergey
-- 
Sergey Petrunia, Software Developer
Monty Program AB, http://askmonty.org
Blog: http://s.petrunia.net/blog