Laurenz Albe <laurenz.albe@xxxxxxxxxxx> writes: > On Tue, 2020-03-17 at 19:57 +0000, Daniel Westermann (DWE) wrote: > >> >> is someone using temporary tablespaces on a RAM disk ? Any experiences with that? >> >> I did some quick tests and checked the archives but could not find any >> >> information that either confirmed it is a bad idea nor the opposite. >> >> >Taking a step back, wouldn't it be better to increase "work_mem" >> >and "temp_buffers" and set "temp_file_limit", so that temporary >> >files are avoided whenever possible and temporary tables are cached? >> >> I don't think you can avoid that for all cases, especially when working >> with large data sets. That was one of the reasons for my initial question. > > But with your proposed setup, any query that needs more temp space > than your RAM disk has will fail. I don't think that is good for large > data sets. Perhaps not, but disk filling on the same volume as WAL is also a serious problem in case the process that eventually took the storage to 100% and got an ENoSpace was the WAL write :-) Er, but any standard 1-tablespace configuration is at risk of that, generally. FWIW > > Setting "work_mem" and "temp_buffers" high, you can use all the RAM > you have, and if it still is not enough, it spills to disk rather than die. > > Yours, > Laurenz Albe > > > > -- Jerry Sievers Postgres DBA/Development Consulting e: postgres.consulting@xxxxxxxxxxx
