Re: Strange error related to temporary tables

Csaba Nagy <nagy(at)ecircle-ag(dot)com> writes:
> create temp table temp_report ...;
> ... do some processing using this table...
> drop table temp_report;
> commit;

> This code occasionally triggered the following error (couldn't reliably
> reproduce):
> ERROR: type "temp_report" already exists

BTW, when this happens, does the error persist? If it's a race
condition you'd expect not (because the guy who successfully created the
temp table would soon drop it again). When we saw this problem before,
we were speculating that a temp table's pg_type row had somehow not
gotten dropped during table drop, which'd lead to a persistent failure.

Note that a "persistent" failure could still only manifest occasionally,
if the unwanted pg_type row were in a high-numbered pg_temp_NNN schema
that doesn't get used often. So i guess the correct thing to do is
"select oid, xmin from pg_type where typname = 'temp_report'" and see
if there are any long-lived entries (xmin far away from the others would
be a tipoff).

regards, tom lane