Re: Partitioned Database and Choosing Subtables

On 3/16/2011 12:40 AM, Alban Hertroys wrote:
>>> Try using "dynamic" sql:
>>>
>>> EXECUTE 'SELECT lions,  tigers, bears, statecode FROM WildLife WHERE
>>> state_pt = ' || statecode INTO ...;
>> Thanks Igor. It was a nice try -- and I thought it would work, but the Planner had other plans. Basically, I tried
theinteractive method using a PREPARE statement with one text parammeter followed by an EXECUTE statement.
Unfortunately,the query still went rummaging across the entire database sequentially. 
>
> That's not the same as using dynamic SQL. In fact, that would behave just like your previous, problematic, query.
>
> Dynamic SQL makes that the planner sees a new query each time, that needs to be planned from scratch.
>
Thanks for explaining this. I think I can just see what you mean. I can
also see that I'm way out of my depth here. It's just so much fun when
you mix deadlines with ignorance.

> If you can't see the forest for the trees,
> cut the trees and you'll see there is no forest.

Good point. I'm feeling a bit chainsaw-ish right now.

--
*Bill Thoen*
GISnet - www.gisnet.com
303-786-9961