On Wed, 2008-06-25 at 23:34 -0400, Robert Haas wrote: > I can predict that Tom will say that the planning time it would take > to avoid this problem isn't justified by the number of queries that it > would improve.
> That's possible, but it's unfortunate that there's no > way to fiddle with the knobs and get the planner to do this kind of > thing when you want it to. I don't think we should invent a new parameter for each new optimisation. We would soon get swamped. IMHO we should have a single parameter which indicates how much planning time we consider acceptable for this query. e.g. optimization_level = 2 (default), varies 1-3 Most automatic optimisation systems allow this kind of setting, whether it be a DBMS, or compilers (e.g. gcc). We should agree a simple framework so that each new category of optimization can be described as being a level X optimisation, or discarded as being never worth the time. We do this with error messages, so why not do this with something to control planning time? -- Simon Riggs www.2ndQuadrant.com PostgreSQL Training, Services and Support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
