Re: [INTERFACES] OIDs in pg_type stable across versions? - Mailing list pgsql-interfaces

From Guido.Goldstein@t-online.de (Guido Goldstein)
Subject Re: [INTERFACES] OIDs in pg_type stable across versions?
Date
Msg-id lt7lui6oxf.fsf@Guido.Goldstein.dialup.t-online.de
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In response to OIDs in pg_type stable across versions?  (Eric Marsden <emarsden@mail.dotcom.fr>)
Responses Re: [INTERFACES] OIDs in pg_type stable across versions?  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-interfaces
Moin!

On 20 Jan 1999 11:16:31 +0100
    Eric Marsden <emarsden@mail.dotcom.fr> wrote:
[snipped - low level interface for scheme]
> The fe-be protocol seems to provide sufficient information to do this
> type coercion: when the backend sends the attribute data in response
> to a SELECT statement, it sends a sequence of tuples (name, type-id,
> size). The type-id is an OID from the pg_type table.
>
> Is is reasonable to assume that these oids will be stable across
> versions and platforms, or will I have to reconstruct a table from
> a `SELECT typname, oid FROM pg_type' each time a connection is
> initiated?

I think, yes you should. Think of user defined types! They will be
stored in pg_types also.

What you can do is: cache and share this type information between all
connections initiated from this process.  And then, from time to time,
reload the type information -- or intercept all changes on pg_type
('listen' command) and reload your type infos then.

> (or maybe there's some simpler way to do the type coercions?)

Not in my field of vision.

HAND
  Guido
--
In the beginning there was nothing, and then even that exploded

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