On Mon, Sep 12, 2011 at 00:22, Tom Lane <t...@sss.pgh.pa.us> wrote: > Well, people seem to think that this is worth pursuing, so here's a > couple of thoughts about what needs to be done to get to something > committable.
Thanks, that's exactly the kind of feedback I need. > IMO this is no good because it means that every intermediate result > computed within the cacheable expression will be leaked into > per_query_memory. Agreed, that's not ideal. > type CacheExpr (that's just the first name that came to mind, maybe > somebody has a better idea) StableConstExpr? But we can leave the bikeshedding for later :) > The planner would have to figure out where to inject > CacheExpr nodes into expression trees --- ideally only the minimum > number of nodes would be added. Yeah, that occured to me, but seemed complicated at first, so I didn't want to do it before having a confirmation from the list. However, after looking at the expression tree walking code for a bit, it doesn't seem that scary anymore. > The other thing that is going to be an issue is that I'm fairly sure > this breaks plpgsql's handling of simple expressions. Oh, I would have never thought of that. Regards, Marti -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
