Обсуждение: OIDs - can they be used for accessing records ?

Hello everyone.
    I am currently designing a DB and was wondering whether the OIDs assigned to
each record could also be used as foreign keys links ? is this a good idea
instead of using sequences ? Pros ? Cons ?


--
Derek Clarkson
Web: http://users/bigpond/net/au/drekka

Derek Clarkson <dhc@bigpond.net.au> writes:
>     I am currently designing a DB and was wondering whether the OIDs assigned to
> each record could also be used as foreign keys links ? is this a good idea
> instead of using sequences ? Pros ? Cons ?

It's usually considered a bad idea, mainly because there's no good way
to dump and reload the data (well, you can use pg_dump's -o switch,
but that's a kluge).  Also you have little or no control over the
possibility of OID wraparound leading to key conflicts.  Sequences are
a much cleaner solution.

Be careful to keep track of whether you're using int4 or int8 sequence
values, and declare the foreign key referencing columns to match.  You
will take a nasty performance hit if they don't match.

            regards, tom lane