Path: utzoo!attcan!uunet!decwrl!sun-barr!apple!agate!pasteur!eden!mao
From: mao@eden (Mike Olson)
Newsgroups: comp.databases
Subject: Re: Postgres (was Re: Public Domain Databases)
Message-ID: <27911@pasteur.Berkeley.EDU>
Date: 17 Sep 90 18:33:40 GMT
References: <556@mcspdx.pdx.csd.mot.com> <27728@pasteur.Berkeley.EDU> <1990Sep14.065746.5711@tukki.jyu.fi> <27803@pasteur.Berkeley.EDU> <CIMSHOP!DAVIDM.90Sep16220527@uunet.UU.NET>
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In <CIMSHOP!DAVIDM.90Sep16220527@uunet.UU.NET>, cimshop!davidm@uunet.UU.NET
(David S. Masterson) writes (re: postgres object identifiers)

> how many OIDs (and, I guess, transaction IDs) will be available
> to a new database?

object id's are longs -- you get 2^32 - 1 of them on all architectures
on which postgres currently runs.  32767 of these are reserved for sytem
use.

transaction id's are 5-byte quantities, so you get 2^40 - 1 of them.

note, however, that these are implementation details, and can be changed
without breaking any other part of the system.  a commercial implementation
would probably choose to increase the number of available object identifiers.

					mike olson
					postgres research group
					uc berkeley
					mao@postgres.berkeley.edu