On Thu, Sep 17, 2015 at 4:22 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Robert Haas <robertmh...@gmail.com> writes: >> On Thu, Sep 17, 2015 at 2:23 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: >>> I can't imagine I'd be doing anything that would break the simple case >>> of "give every node a distinct ID". If you are building in weird >>> assumptions about traversal order, that might indeed be a problem. > >> Good to know, thanks. With the design you proposal above, we can make >> this insensitive to traversal order. The only thing that would cause >> trouble is if you somehow ended up with massive gaps in the numbering >> sequence - e.g. if the final plan had 6 nodes, but the IDs were all 5 >> digit numbers, you'd waste a silly amount of memory relative to the >> size of the plan. But a few gaps (e.g. for removed SubqueryScan >> nodes) won't be a problem. > > Hm ... if you quit worrying about the order-of-assignment, maybe you > could prevent gaps from removed SubqueryScan nodes by not giving them > IDs until after that decision is made?
Hmm, that might work. I'll try it. > Although it may not be worth > any extra trouble. Right. If it doesn't turn out to be easy, I won't worry about it. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
