Re: pg_toast_temp_xx AND pg_temp_xx SCHEMAS

> They're just there to hold temporary tables (so that the names of such
> tables don't conflict with any non-temporary tables).  The reason they
> seem to accumulate is we only create one when needed, and there's one
> for each concurrently executing backend if it creates any temp tables.

Hm, do they get garbage-collected in any way? I have several such schemes that won't disappear even though no other sessions but one is there.
On a side note: I can drop temporary tables of other sessions via "DROP pg_temp_xx.table" (although I can't seem to affect table data seen from other session). Is there any security issues/gotchas here?