| 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 |
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| 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)
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