"Andrus" <eetasoft@online.ee> writes:
> select * from information_schema.key_column_usage
> returns
> ERROR: more than one row returned by a subquery used as an expression
There's a known bug of that ilk in 8.2beta, but I don't see how it could
happen in 8.1 ... you sure you're seeing this on 8.1.1?
regards, tom lane