On Thu, Feb 25, 2010 at 22:11, Tom Lane <t...@sss.pgh.pa.us> wrote: > Alex Hunsaker <bada...@gmail.com> writes: > Uh, no, this isn't about saving either parse time or bandwidth. > The discussion is about when to expend more planning time in hopes > of getting better plans.
This is what im tripping over: > > Bruce's suggestion that we should provide some user control over whether we > > plan at bind time or execute time Let me see if I can sum up what I was trying to say: Prepared plans + bind plan (what we have now): Use: when you have a query that takes a long time to plan Problems: if you use parameters you might no get a good plan Solution: if you have stable parameters dont pass them as such, inline them Better: If we could figure out and make we could make better plans on the fly and use them [ aka if you have a good driver you can easily control if its a prepared statement or not without changing how you quote or inline your sql ] Prepared plans + exec plan (new guc/ protocol thing): Use: not quite sure Problems: slow because it would replan every time Solutions: use a prepared plan with the appropriate things not parametrized...? [ aka we already have this, its called dont use a prepared statement ] Whats the benefit of prepare + exec plan vs just inlining? What do you save? Some parse time? Some bandwidth? Yeah if its a smart knob that does things like "Oh, I see I have an mvc for that param, ill give you a better plan". OK, But the knob no longer means plan at execute time. It more in the realm of what Tom is suggesting IMHO. Anyway I feel like im probably just violently agreeing. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
