From: | Simon Riggs <simon(at)2ndquadrant(dot)com> |
---|---|
To: | Gavin Sherry <swm(at)alcove(dot)com(dot)au> |
Cc: | pgsql-hackers(at)postgresql(dot)org |
Subject: | Re: Dynamic Partitioning using Segment Visibility Maps |
Date: | 2008-01-11 08:07:18 |
Message-ID: | 1200038838.4266.887.camel@ebony.site |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On Fri, 2008-01-11 at 02:28 +0100, Gavin Sherry wrote:
> On Thu, Jan 10, 2008 at 09:30:10PM +0000, Simon Riggs wrote:
> > > > We cannot perform partition exclusion using this type of WHERE clause at
> > > > planning time because the CURRENT DATE function is STABLE.
> > >
> > > We can do the exact same thing -- if it's a direction people want to
> > > take. In fact, we can do it better/faster because once we've evaluated one
> > > partition we know that there are no others to evaluate.
> >
> > Lost you completely here. I'm explaining to you that *nobody* can solve
> > those problems solely at planning time, by definition, so it has to be
> > done at execution time. I'm not saying anything about your way, my way.
>
> Sorry, I wasn't clear enough. I was trying to say, if we're going to do
> something in the executor (for right or wrong) the declarative approach
> can do it too. Since there will be partition bounding information
> available, we can do partition selection in the executor (maybe the
> planner should tell us to do it).
Of course. It's an identical situation for both. Regrettably, none of
your comments about dynamic partitioning and planning were accurate as a
result.
> Okay. As I said above, nothing in declarative partitioning rules out
> partition selection with stable functions. So, we lets do it, assuming
> everyone else thinks it is a good idea.
If you check the archives this was long ago been identified as a
requirement. And I said exactly the things you said, BTW, when trying to
say it didn't matter.
I've kept a list of requests for improvement that I can share with you;
I've always been loathe to publish a list of bad points.
--
Simon Riggs
2ndQuadrant http://www.2ndQuadrant.com
From | Date | Subject | |
---|---|---|---|
Next Message | Dave Page | 2008-01-11 08:47:56 | Re: Pl/Java broken since Postgresql 8.3-rc1 |
Previous Message | Sim Zacks | 2008-01-11 07:42:47 | Re: 8.2.4 serious slowdown |