On Sat, Feb 26, 2011 at 12:30 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Robert Haas <robertmh...@gmail.com> writes: >> Yay! I'm excited about this, particularly the possible "pipelining" >> stuff, where you can do WITH (DELETE .. RETURNING ..) INSERT ... and >> have it be like cool and fast and stuff. > >> Or at least I hope you can do that. > > It's gonna need some work yet. As things stand, the tuples are indeed > pipelined through, but the CteScan nodes *also* stash them aside into > tuplestores, just in case somebody demands a rescan. Fixing that will > require revisiting the exec flags (EXEC_FLAG_REWIND etc). We don't > currently distinguish "it's unlikely you'll have to rescan" from > "you're guaranteed not to have to rescan", but a CteScan that's covering > a ModifyTable has to know the latter to not have to keep hold of copies > of the RETURNING tuples. > > It might be a small enough change to do after alpha starts, but I don't > have time for it right now.
Well, if nothing else, the potential is there for a future release. I'm probably not quite as excited about this feature as David Fetter (and my 100-Watt lightbulb is not quite as bright as the sun at high noon in midsummer) but I do think it's pretty cool, and I appreciate you getting it in, even in a somewhat basic form. -- 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
