On Mon, Dec 6, 2010 at 10:40 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Robert Haas <robertmh...@gmail.com> writes: >> On Mon, Dec 6, 2010 at 9:45 AM, Heikki Linnakangas >> <heikki.linnakan...@enterprisedb.com> wrote: >>> Well, then you need some sort of cross-backend communication, which is >>> always a bit clumsy. > >> A temp file seems quite sufficient, and not at all difficult. > > "Not at all difficult" is nonsense. To do that, you need to invent some > mechanism for sender and receivers to identify which temp file they want > to use,
Why is this even remotely hard? That's the whole point of having the "publish" operation return a token. The token either is, or uniquely identifies, the file name. > and you need to think of some way to clean up the files when the > client forgets to tell you to do so. That's going to be at least as > ugly as anything else. Backends don't forget to call their end-of-transaction hooks, do they? They might crash, but we already have code to remove temp files on server restart. At most it would need minor adjustment. > And I think it's unproven that this approach > would be security-hole-free either. For instance, what about some other > session overwriting pg_dump's snapshot temp file? Why would this be any different from any other temp file? We surely must have a mechanism in place to ensure that the temporary files used by sorts or hash joins don't get overwritten by some other session, or the system would be totally unstable. -- 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
