X-Original-To: pgsql-hackers@postgresql.org Received: from spampd.localdomain (postgresql.org [64.49.215.8]) by postgresql.org (Postfix) with ESMTP id 63FB4475458 for ; Tue, 15 Apr 2003 19:18:23 -0400 (EDT) Received: from sss.pgh.pa.us (unknown [192.204.191.242]) by postgresql.org (Postfix) with ESMTP id A1802474E44 for ; Tue, 15 Apr 2003 19:18:22 -0400 (EDT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.12.9/8.12.9) with ESMTP id h3FNIOU6010858; Tue, 15 Apr 2003 19:18:24 -0400 (EDT) To: bruc@acm.org Cc: pgsql-hackers@postgresql.org Subject: Re: Are we losing momentum? In-reply-to: <200304152254.h3FMsrwe047585@stone.congenomics.com> References: <200304152254.h3FMsrwe047585@stone.congenomics.com> Comments: In-reply-to "Robert E. Bruccoleri" message dated "Tue, 15 Apr 2003 18:54:53 -0400" Date: Tue, 15 Apr 2003 19:18:24 -0400 Message-ID: <10857.1050448704@sss.pgh.pa.us> From: Tom Lane X-Spam-Status: No, hits=-32.3 required=5.0 tests=BAYES_00,EMAIL_ATTRIBUTION,IN_REP_TO,QUOTED_EMAIL_TEXT, REFERENCES,REPLY_WITH_QUOTES autolearn=ham version=2.50 X-Spam-Level: X-Spam-Checker-Version: SpamAssassin 2.50 (1.173-2003-02-20-exp) X-Archive-Number: 200304/541 X-Sequence-Number: 38031 "Robert E. Bruccoleri" writes: > I beg to differ with Tom Lane's opinion, but schemas do not solve the > problem with multi-database queries because of the following reasons: > 1) When dealing with large databases, the use of multiple databases > reduces the risk of wiping out all the data, and reduces the recovery > time in case of accidents. > 2) Multiple databases allow for different management policies on each > database, whereas schemas require some consistency across them all. > In a heterogeneous working environment, this is a signficant issue. > 3) PostgreSQL should strive for heterogeneous multi-database queries, > so that applications currently using other systems could be slowly > migrated to PostgreSQL by moving portions of a database from other > vendors to PostgreSQL. In my work, the lack of PostgreSQL - Oracle > connectivity is a disabling impediment to wider PostgreSQL usage. Please keep in mind that I was replying to a poster who said "cross-db queries on the same server (meaning same postmaster, for our purposes) are trivial; why hasn't Postgres got them when everybody else does?" Your above arguments are all good ones, but they presume a scenario that is much different and *MUCH* harder to implement than local "cross database" queries. My point is that schemas solve the same-server problems that the original poster was interested in. I did not say, nor mean, that there is no need for cross-server queries. But that is a different problem. Today we can only offer dblink; maybe someday SQL-MED. regards, tom lane