Re: global temporary tables
decibel <decibel@decibel.org>
From: Jim Nasby <decibel@decibel.org>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Robert Haas <robertmhaas@gmail.com>, Greg Sabino Mullane <greg@turnstep.com>, pgsql-hackers@postgresql.org
Date: 2010-04-25T14:26:37Z
Lists: pgsql-hackers
On Apr 24, 2010, at 10:02 PM, Tom Lane wrote: > Robert Haas <robertmhaas@gmail.com> writes: >> Pushing it into the RelFileNode has some advantages in terms of being >> able to get at the information from everywhere, but one thing that >> makes me think that's probably not a good decision is that we somtimes >> WAL-log relfilenodes. And WAL-logging the value of the isTemp flag is >> a waste, because if we're WAL-logging, it's zero. > > Yeah. I think we also use RelFileNode as a hash tag in places, and > so adding a bool to it would be problematic for a couple of reasons: > possibly uninitialized pad bytes, and uselessly incorporating more bytes > into the hash calculation. Do we need to hash it that frequently? Do we insert tons of them into WAL? Worrying about those cases smells like premature optimization, but admittedly I don't have enough knowledge here... -- Jim C. Nasby, Database Architect jim@nasby.net 512.569.9461 (cell) http://jim.nasby.net