change in behaviour? Is this a regression in function?

Hi all,

Sorry if this is the wrong mailing list, I couldn't see a "help" type
list.

Under Postgresql 7.1.3, I could use "create table foo as select * from
bar" and the table would be created with OIDs.

Under Postgres 7.3.1, this no longer seems to be the case:

> test=> select oid from bar;
> oid
> --------
> 17168
> 17175
> (2 rows)
>
> test=> create table foo as select * from bar;
> SELECT
> test=> select oid from foo;
> ERROR: Attribute "oid" not found

Compare this with version 7.1.3, on a different box:

> test=> select oid from bar;
> oid
> --------
> 102406
> 102526
> (2 rows)
>
> test=> create table foo as select * from bar;
> SELECT
> test=> select oid from foo;
> oid
> --------
> 104307
> 104308
> (2 rows)

Is this a configuration problem at my end (I can't see anything wrong, but
the two versions are on different machines) or is it a problem with
version 7.3.1. Or was I simply relying on an undocumented feature? If the
latter, what is the best way of getting round this? Both versions are
running on FreeBSD, and were compiled from source, if it helps. They are
using the standard config files, but have the pg_hba access permissions
locked down to one specific IP address.

Thanks,

Gavin