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 ---------------------------(end of broadcast)--------------------------- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate
