Joseph Shraibman <jks(at)selectacast(dot)net> writes:
> playpen=# select lastchg_addto('foo','c');
> ERROR: plpgsql: cache lookup from pg_proc failed
Somewhere you've got a stored plan --- probably a view or rule or
trigger, if it persists across backend runs --- that refers to a plpgsql
function that no longer exists (at least not under the same OID). You
need to drop and recreate that view or whatever. Unfortunately you
haven't shown us enough info to guess which one...
regards, tom lane