On Thu, Jul 16, 2009 at 4:16 PM, Tom Lane<t...@sss.pgh.pa.us> wrote: > However, I do observe that this seems a sufficient counterexample > against the theory that we can just remove the collapse limits and let > GEQO save us on very complex queries. On my machine, the example query > takes about 22 seconds to plan using CVS HEAD w/ all default settings. > If I set both collapse_limit variables to very high values (I used 999), > it takes ... um ... not sure; I gave up waiting after half an hour.
What's the point of GEQO if it doesn't guarantee to produce the optimal plana and *also* doesn't guarantee to produce some plan, any plan, within some reasonable amount of time? Either we need to fix that or else I don't see what it's buying us over our regular planner which also might not produce a plan within a reasonable amount of time but at least if it does it'll be the right plan. -- greg http://mit.edu/~gsstark/resume.pdf -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
