On 2004-11-11 19:49:53 +0000 Chris Green <chris@areti.co.uk> wrote:
PostgreSQL every row has associated with it a unique indeitifier called the oid, which can be retrieved along with the row data; [...]
Ahhh! I remember this now! I just dug it out of the PostgreSQL manual, which you can find online at http://www.postgresql.org/docs/7.4/static/datatype-oid.html and it explains why using them is discouraged: Also, an OID system column is added to user-created tables (unless WITHOUT OIDS is specified at table creation time). [...] The oid type is currently implemented as an unsigned four-byte integer. Therefore, it is not large enough to provide database-wide uniqueness in large databases, or even in large individual tables. So, using a user-created table's OID column as a primary key is discouraged. [...] Thanks for the reminder that they're there, though! -- MJR/slef My Opinion Only and not of any group I know Creative copyleft computing - http://www.ttllp.co.uk/ Unsolicited attachments to the pipex address deleted Will HLF fund tree-killings? http://www.thewalks.co.uk/