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From: Tom Lane <tgl@sss.pgh.pa.us>
To: ZongtianHou <zongtianhou@icloud.com>
cc: pgsql-admin <pgsql-admin@postgresql.org>
Subject: Re: Schema and Namespace Oid confusion
In-reply-to: <860D4620-5D8C-4D24-991B-6B18F2BC94A5@icloud.com>
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Comments: In-reply-to ZongtianHou <zongtianhou@icloud.com>
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ZongtianHou <zongtianhou@icloud.com> writes:
> First, what is the difference between namespace and schema?

None.

> Second, why the Oid of public namespace is 2200, the same between databa=
ses? Does oid is unique for every object across cluster? =


CREATE DATABASE physically clones the template database, so all objects
have the same OIDs they had in the template.  OID uniqueness is only
expected for objects within one database (and even then, only across
objects in the same system catalog), not across the whole cluster.

			regards, tom lane