Re: OID
От | Oliver Elphick |
---|---|
Тема | Re: OID |
Дата | |
Msg-id | 1014280223.13241.123.camel@linda обсуждение исходный текст |
Ответ на | OID (virka prasetia <virka@kmrg.lib.itb.ac.id>) |
Список | pgsql-general |
On Thu, 2002-02-21 at 12:29, virka prasetia wrote: > > hi i'm new in psql, and i want to know several things: > 1. is it possible to use oid of a table for reference attribute in another > table ? It is possible, but it is a bad design. Oids are not preserved in a dump, unless that is specifically requested. They might even go away altogether, since they are an internal feature, not part of your schema. If you need a key field, create one; use the SERIAL datatype to get a unique number. > 2. is it possible to compare oid of a class, using comparison operator > (like,=, etc)? I don't know what you mean by this. Oids are arbitrary numbers consecutively assigned. You can use "oid = xxx" to identify a row, but no other comparison is meaningful. You can't even use "oid > xxx" to identify rows added later, since oids will wrap round at the end of their range. -- Oliver Elphick Oliver.Elphick@lfix.co.uk Isle of Wight http://www.lfix.co.uk/oliver GPG: 1024D/3E1D0C1C: CA12 09E0 E8D5 8870 5839 932A 614D 4C34 3E1D 0C1C "My sheep hear my voice, and I know them, and they follow me; And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand." John 10:27,28
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