From: | Alvaro Herrera <alvherre(at)dcc(dot)uchile(dot)cl> |
---|---|
To: | Simon Riggs <simon(at)2ndquadrant(dot)com>, pgsql-performance(at)postgresql(dot)org |
Cc: | elein <elein(at)varlena(dot)com> |
Subject: | Re: [Fwd: Re: Functionscan estimates] |
Date: | 2005-04-14 18:58:09 |
Message-ID: | 20050414185809.GD28198@dcc.uchile.cl |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-performance |
On Thu, Apr 14, 2005 at 10:39:03AM -0700, elein wrote:
> All functions could have a cost associated with them, set by the writer of
> the function in order for the planner to reorder function calls.
> The stonebraker airplane level example was:
> select ... from ... where f(id) = 3 and expensive_image_function(img)
> The idea, of course is to weight the expensive function so it was
> pushed to the end of the execution.
So there was only a constant cost associated with the function? No
estimator function, for example?
--
Alvaro Herrera (<alvherre[(at)]dcc(dot)uchile(dot)cl>)
"If you have nothing to say, maybe you need just the right tool to help you
not say it." (New York Times, about Microsoft PowerPoint)
From | Date | Subject | |
---|---|---|---|
Next Message | Joshua D. Drake | 2005-04-14 19:16:55 | Re: How to improve db performance with $7K? |
Previous Message | Dave Held | 2005-04-14 18:46:12 | Re: How to improve db performance with $7K? |