Re: Work_mem

With pg_stat_activity, you would need to catch them "in the act", but there are no columns there which describe temp file usage anyway.

pg_stat_statements has the columns "temp_blks_read" and "temp_blks_written", in all supported versions, so you should be able to spot the queries using temp files there.  Unless maybe your pg_stat_statements.max setting is too low and those queries are forced out.

Or you could set log_temp_files = 0.  That would log all statements using temp files into the PostgreSQL server log.

Cheers,

Jeff