Re: Using oids
От | Bo Lorentsen |
---|---|
Тема | Re: Using oids |
Дата | |
Msg-id | 1062602651.7851.146.camel@localhost обсуждение исходный текст |
Ответ на | Re: Using oids (Tom Lane <tgl@sss.pgh.pa.us>) |
Ответы |
Re: Using oids
Re: Using oids |
Список | pgsql-general |
On Wed, 2003-09-03 at 16:13, Tom Lane wrote: > The reason OIDs shouldn't be considered unique is that there is no > mechanism to enforce that they are unique --- unless you make one, > that is, create a unique index on OID for a table. The system does > not do that for you since it would be excessive overhead for tables > in which the user doesn't care about OID uniqueness. But I'd > definitely recommend it if you are using OIDs for row identifiers. Ok, so my little INSERT / SELECT show will continue to work for a long time, as I only uses the oids on short term bacis. > If you want a globally unique ID based on OIDs, use the table OID > concatenated with the row OID. Ok, this make sense ! > No, there isn't. There is only ctid, which is not useful as a long-term > row identifier, because UPDATE and VACUUM can change it. But there is no way for the client user to user these in a "PQgetLastCtid" and "SELECT * from zxy where ctid = 42", so this will not help :-) Thanks anyway, may oid's live for a long time, and one day become grown up 64 bit values :-) /BL
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