Re: Re: [SQL] oracle rownum equivalent?
От | mikeo |
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Тема | Re: Re: [SQL] oracle rownum equivalent? |
Дата | |
Msg-id | 3.0.1.32.20000608082010.0092bdb0@pop.spectrumtelecorp.com обсуждение исходный текст |
Ответ на | Re: Re: [SQL] oracle rownum equivalent? ("Cary O'Brien" <cobrien@Radix.Net>) |
Ответы |
Re: Re: [SQL] oracle rownum equivalent?
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Список | pgsql-general |
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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