Tom Lane wrote: > Martijn van Oosterhout <[EMAIL PROTECTED]> writes: > > I don't think temporary tables have any special rules regarding disk > > writes, so I'd expect them ot get written out like everything else. > > They'll be written out from PG's internal buffers, but IIRC they will > never be fsync'd, and they definitely aren't WAL-logged. (These > statements hold true in 8.0, but not sure how far back.) > > In principle, therefore, the kernel could hold temp table data in its > own disk buffers and never write it out to disk until the file is > deleted. In practice, of course, the kernel doesn't know the data is > transient and will probably push it out whenever it has nothing else to > do. > > One of the things on the TODO list is making the size of temp-table > buffers user-configurable. (Temp table buffers are per-backend, they > are not part of the shared buffer arena.) With a large temp-table arena > we'd never need to write to the kernel in the first place. Right now > you could manually increase the #define that sets it, but it would not > pay to make it very large because the management algorithms are very > stupid (linear scans). That has to be fixed first :-(
I assume you mean your TODO list because the official one has no mention of this. -- Bruce Momjian | http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
