The following bug has been logged online:
Bug reference: 2016
Logged by: Pit Mueller
Email address: fmi-soft(at)gmx(dot)de
PostgreSQL version: 8.1 BETA4
Operating system: WinXP
Description: query working with 8.0 fails with 8.1
Details:
Using this query to get the primary key for a certain table:
SELECT p.conname AS constraint_name FROM pg_constraint p WHERE p.contype =
'p' AND p.conrelid = pg_class.oid AND pg_class.relname = 'mytablename'
leads to an error:
ERROR: missing FROM-clause entry for table "pg_class"
This query worked fine with 8.0.3.