At 06:47 PM 6/7/00 -0400, Cary O'Brien wrote:
>
>> thanks for the response. oid is equivalent to oracle rowid.
>
>I think there is a fundamentel difference between oid and rownum.
>Oid is just a serial number. Rownum is a long string that tells
>oracle where exactly the row is. So *I think* rownum can be
>used for fast lookups, where oid, unless indexed, can't.
>
>Other than that they are the same pretty much.
>
>-- cary
>
i'll have to respectfully disagree with you on your interpretation of
rownum.
in oracle, rownum tells only the relative position of a row in a result set.
also, it is an integer value starting at 1 up to nrows retrieved and is used,
for the most part, to limit the result set and not for fast lookups. it also
can be used in a DML statement within a function, such as mod(), to aid in
generating a value. the point here is moot though, as postgres doesn't have
an equivalent and i'll have to learn to live without that small piece of
oracle and enjoy what i see as the greater benefits of postgres.
:) mikeo