Bartosz Dmytrak <bdmytrak(at)gmail(dot)com> writes:
> This e-mail is reposted form pgadmin support mailing list. This problem
> looks like related with postgres not pgAdmin.
> [ EXPLAIN VERBOSE yields a "cache lookup failed" error ]
Huh, yeah, that's a backend bug all right. I thought at first you might
have a catalog-corruption problem, but I can reproduce the failure here
from your example. Most likely EXPLAIN is getting confused about which
Var belongs to which table. Will look into it.
regards, tom lane