Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1u55Jt-00By8c-4g for pgsql-general@arkaria.postgresql.org; Wed, 16 Apr 2025 16:09:01 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.94.2) (envelope-from ) id 1u55Jr-000BdG-4T for pgsql-general@arkaria.postgresql.org; Wed, 16 Apr 2025 16:08:59 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1u55Jq-000Bd7-PL for pgsql-general@lists.postgresql.org; Wed, 16 Apr 2025 16:08:59 +0000 Received: from sss.pgh.pa.us ([68.162.161.243]) by makus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1u55Jp-000OZr-17 for pgsql-general@lists.postgresql.org; Wed, 16 Apr 2025 16:08:58 +0000 Received: from sss1.sss.pgh.pa.us (localhost [127.0.0.1]) by sss.pgh.pa.us (8.15.2/8.15.2) with ESMTP id 53GG8rJ51908456; Wed, 16 Apr 2025 12:08:53 -0400 From: Tom Lane To: "David G. Johnston" cc: Dominique Devienne , Laurenz Albe , Adrian Klaver , Igor Korot , "pgsql-generallists.postgresql.org" Subject: Re: Fwd: Identify system databases In-reply-to: References: <817abeac-d628-4279-bfef-9e1e3aa1884b@aklaver.com> <25b6cd49-f871-47fe-bf3b-5416637736ca@aklaver.com> <2dffe860b085b927726a052bcfe16ede704ab923.camel@cybertec.at> <1898934.1744814354@sss.pgh.pa.us> Comments: In-reply-to "David G. Johnston" message dated "Wed, 16 Apr 2025 08:25:12 -0700" MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <1908454.1744819733.1@sss.pgh.pa.us> Date: Wed, 16 Apr 2025 12:08:53 -0400 Message-ID: <1908455.1744819733@sss.pgh.pa.us> List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk "David G. Johnston" writes: > But feel free to work out a design and add it to the ToDo list for the v4 > protocol. The use case seems reasonable and doable (on the basis of the > replication protocol works). No, the replication protocol isn't a precedent. Physical replication needn't connect to a particular database because it does no catalog accesses (and hence can't run SQL). All it's able to do is suck out the WAL stream. Logical replication can do SQL --- but it has to connect to a specific database. regards, tom lane