Why doesn't this work:
test=# select oid, relname, indisclustered from pg_index join pg_class 
on indexrelid=oid where indexrelid > 17205;
ERROR:  column "oid" does not exist
I'm _joining_ on the oid column.
If I qualify it, it works:
test=# select pg_class.oid, relname, indisclustered from pg_index join 
pg_class on indexrelid=oid where indexrelid > 17205;  oid  |   relname    | indisclustered
-------+--------------+---------------- 17214 | child_b_key  | t 17210 | parent_a_key | t
(2 rows)
I can't see that I've made an error in the first example - is it a 
Postgres bug?
Chris