Обсуждение: OIDS

Hi All,

I have 7.4.7 version, my question is what are OIDS user for? What can
one do with it!

Thanks,
Hrishi

Hrishikesh Deshmukh writes:

>I have 7.4.7 version, my question is what are OIDS user for? What can
>one do with it!

they're for internal use only, they may go away, so don't do anything
with them, pretend that they aren't even there.

richard

Am Montag, den 20.06.2005, 11:57 -0400 schrieb Hrishikesh Deshmukh:
> Hi All,
>
> I have 7.4.7 version, my question is what are OIDS user for? What can
> one do with it!

Google or your favourite search engine helps :-)

http://www.postgresql.org/files/documentation/books/aw_pgsql/node71.html

is among the first results.

The usual postgres documentation included in your distribution and also
online is of great help. I suggest reading it a bit.

Tino Wildenhain wrote:
> Google or your favourite search engine helps :-)
>
> http://www.postgresql.org/files/documentation/books/aw_pgsql/node71.html
>
> is among the first results.

Unfortunately those docs are quite out of date. This page is better:

http://developer.postgresql.org/docs/postgres/datatype-oid.html

(This describes the behavior that will be the default in 8.1)

Specifically:

Object identifiers (OIDs) are used internally by PostgreSQL as primary
keys for various system tables.... The oid type is currently implemented
as an unsigned four-byte integer. Therefore, it is not large enough to
provide database-wide uniqueness in large databases, or even in large
individual tables. So, using a user-created table's OID column as a
primary key is discouraged. OIDs are best used only for references to
system tables.

-Neil