From: | mikeo <mikeo(at)spectrumtelecorp(dot)com> |
---|---|
To: | "Cary O'Brien" <cobrien(at)Radix(dot)Net>, pgsql-general(at)hub(dot)org |
Subject: | Re: Re: [SQL] oracle rownum equivalent? |
Date: | 2000-06-08 12:20:10 |
Message-ID: | 3.0.1.32.20000608082010.0092bdb0@pop.spectrumtelecorp.com |
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Lists: | pgsql-general pgsql-sql |
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
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