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 1v4hWV-004re1-6b for pgsql-general@arkaria.postgresql.org; Fri, 03 Oct 2025 15:16:43 +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 1v4hWT-00EBIf-9n for pgsql-general@arkaria.postgresql.org; Fri, 03 Oct 2025 15:16:41 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1v4hWS-00EBIX-UY for pgsql-general@lists.postgresql.org; Fri, 03 Oct 2025 15:16:41 +0000 Received: from mail-vk1-xa31.google.com ([2607:f8b0:4864:20::a31]) by magus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.96) (envelope-from ) id 1v4hWR-000DWR-1U for pgsql-general@postgresql.org; Fri, 03 Oct 2025 15:16:41 +0000 Received: by mail-vk1-xa31.google.com with SMTP id 71dfb90a1353d-54aa789f9b5so1712315e0c.1 for ; Fri, 03 Oct 2025 08:16:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1759504598; x=1760109398; darn=postgresql.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=JNF03BZsXrGapmAIkshe9M8Hny/9LIVV6RfI0WgOocU=; b=m0ODz1bDIeYtsbzmqy62ZHOzvkbZtVkpWgl71zukqWk2gPm8Kp2LMUkiH9z8aAa51C ScZ64bBaOzJ+bBEBxJExe115Py+qK52dyPL4ymALXF271pDDoy5hZmnjkpgRO8KimQUm 0YXg08FpxRXeQBG9eBi9v5iqKk830igDn3Im3np6lQQuNsMd1Jlp+0XOBM5pPJ2wRCTp W1umwPIiQp0e1ck8Lz7WxXv7ijazM/hFw2vJ2aq9gYhq8sNpJ98O0WhqRp/H8tvfrgUP AJKhSrucw2L9W8SltJtzU559oVPhS0scSHWT3z8XspP2pJwun5YxoLI1fzE4h8gnLGoU EDGQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1759504598; x=1760109398; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=JNF03BZsXrGapmAIkshe9M8Hny/9LIVV6RfI0WgOocU=; b=aWAA03326GvBXVt1w2rchX7CzURsUiqb4o6MPzLJ8TrBuOwDRvpgehawwbv+dlHyze 5PS/ANcEXapgpSXYv5zA8HJSxfUxldF8bXhx92iDl42sNnSIp8GRzwV0qg9R6oWdRmeb C2V304K7c5YOFx/0MSTD8DMX2lVkdAnh5GwKMplOBJmOu2LNaO68MBHiAl2XjkZ3v1nn gouBERvbaNy2fZAjpDVeMTin/ml3JDrg1RNgwCE82W9mTVf/5jfOKYya1wjQaCV+NG/z LEn6S7aoThCjuBFecQ/hlGBezP30a15GWOn5DXmxmOKtfpgH2qsGu70y+FU+CM2C6AE/ iRug== X-Forwarded-Encrypted: i=1; AJvYcCVilwQTVv5Hm36dv/qdacn+3v6FV3VoUZu+SyIfbTBXwEpxe5sJVhHJ3oYsDK1lybjGwWlIMlfSfuP760Vs@postgresql.org X-Gm-Message-State: AOJu0Ywt1fXDCiUDP1+28JjY2+PDTEIW2bFLehfxdlmUAjgYCSc6H3j4 1Vbmst6Ev9lj/uLIrhJ/+gPyeZySFxGnc8+JjfdqY81pWx34t6jdWqLa07c4a2Py3YCgda+0piH SH8VwPga2XZ1/509drf/e7jYRDCRwGAo= X-Gm-Gg: ASbGncuCpQXdFRibh0eU9c1bGKmEGN+QImCM4AtnRH9GhRxV/qt8hNfaIc/RjrS2IhD WKVnzYK/p550Gt3KzWzyLKzSLFAvSRv6cwjKp0ngc6Dsi1+gwRSPJ2ArPh/E7zT5KB5Xl7KULFf PRfU84A8EFq3IvkH6f1QtDKlySMC/M6RT7VAZ6gCUcqOUU3GtXiliJ2nixvm0/yLEFFvk97KG0d BqRgcZL/eamHKxPaUhY+ixDSDjo+4Cp X-Google-Smtp-Source: AGHT+IEPjuMcn6NxG3OKSqx/nUfSSUTBXdruYiK8H0Oe9IK49o2G8qiD2fA4oFWwIkhsT1sGUrcg9cbgy60EL6v1S70= X-Received: by 2002:a05:6122:8d0:b0:54a:70d3:66b0 with SMTP id 71dfb90a1353d-5524ea6867dmr1362669e0c.12.1759504597817; Fri, 03 Oct 2025 08:16:37 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Pavan Kumar Date: Fri, 3 Oct 2025 10:15:58 -0500 X-Gm-Features: AS18NWDWL62FoP5hR5dpeRZ3O9pe5hvYDLgPTyaapIJp4oFcwFMDBkxeGTfBpqk Message-ID: Subject: Re: Downgrade pgsql 17 to pgsql 12 question To: Ashish Mukherjee Cc: Merlin Moncure , pgsql-general@postgresql.org Content-Type: multipart/alternative; boundary="000000000000889df706404296e4" List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk --000000000000889df706404296e4 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hello Ashish Mukherjee, Did you get a chance to disable JIT related parameters after PG 17 upgrade ? If your database size in TB , try to consider pglogical bi directional replication. you will have 17.x version and 12.x version. if you ran in to any issue you can always switch back to old version. I am not sure TDE supported bi directional replication On Tue, Sep 30, 2025 at 3:23=E2=80=AFAM Ashish Mukherjee wrote: > Thank you all for your inputs. > > Well, Percona TDE was leading to the queries being very inefficient / slo= w > after upgrading to pgsql 17. Explain analyze shows that query planning ti= me > shoots up crazily. A decision was taken to go back to pgsql 12, which > worked out fine as there was no incompatibility. I restored from the bina= ry > dump with the -j option, as our database is huge. I completely agree that > downgrade is not a good option but a pragmatic one under the circumstance= s. > > Now the consideration is to use some other encryption option for the > database which will work fine on pgsql 17. Cybertec's technology is one > route, the other is EDB. I am happy to hear experiences of folks here wit= h > pgsql encryption options for v17 on large databases (2.5T in our case). > > On Mon, Sep 29, 2025 at 5:10=E2=80=AFAM Merlin Moncure wrote: > >> On Fri, Sep 26, 2025 at 8:16=E2=80=AFAM Ashish Mukherjee < >> ashish.mukherjee@gmail.com> wrote: >> >>> Hello, >>> >>> I have a strange requirement to downgrade from pgsql 17 to pgsql 12. >>> This is because we found in production certain incompatibilities betwee= n >>> both versions for our database. It should have been caught in testing b= ut >>> was not. >>> >> >> Agree with others that snap downgrade is not necessarily a good choice >> here. Either way, if I were in your shoes, I'd be loading a plain text >> dump, maybe with some light massaging to strip out some compatibility >> issues. >> >> Can you let us know what the hang up is? Version upgrades these days ar= e >> usually pretty painless except for some performance issues, unless you h= ave >> some unusual situations, for example, exotic extensions. >> >> merlin >> >> --=20 *Regards,#! Pavan Kumar----------------------------------------------*- *Sr. Database Administrator..!* *NEXT GENERATION PROFESSIONALS, LLC* *Cell # 267-799-3182 # pavan.dba27 (Gtalk) * *India # 9000459083* *Take Risks; if you win, you will be very happy. If you lose you will be Wise * --000000000000889df706404296e4 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hello Ashish Mukherjee,

Did you get a c= hance to disable JIT related parameters after=C2=A0 PG 17=C2=A0 upgrade ?= =C2=A0

If your database size in TB , try to consid= er pglogical bi directional replication. you will have 17.x version and 12.= x version. if you ran in to any issue you can always switch back to old ver= sion.
I am not sure TDE supported bi directional=C2=A0replication= =C2=A0



On Tue, Sep= 30, 2025 at 3:23=E2=80=AFAM Ashish Mukherjee <ashish.mukherjee@gmail.com> wrote:
Thank you a= ll for your inputs.

Well, Percona TDE was leading to the= queries being very inefficient / slow after upgrading to pgsql 17. Explain= analyze shows that query planning time shoots up crazily. A decision was t= aken to go back to pgsql 12, which worked out fine as there was no incompat= ibility. I restored from the binary dump with the -j option, as our databas= e is huge. I completely agree that downgrade is not a good option but a pra= gmatic one under the circumstances.=C2=A0

Now the = consideration is to use some other encryption option for the database which= will work fine on pgsql 17. Cybertec's technology is one route, the ot= her is EDB. I am happy to hear experiences of folks here with pgsql encrypt= ion options for v17 on large databases (2.5T in our case).

<= div class=3D"gmail_quote">
On Mon, Sep= 29, 2025 at 5:10=E2=80=AFAM Merlin Moncure <mmoncure@gmail.com> wrote:
On Fri, Sep 26, 2025 at 8:16=E2=80=AFAM Ashish Mukherjee <ashish.mukherjee@g= mail.com> wrote:
Hello,

I have a strange requirement to downgrade from pgsql 17 to pgsql 12. This = is because we found in production certain incompatibilities=C2=A0between bo= th versions for our database. It should have been caught in testing but was= not.

Agree with others tha= t snap downgrade is not necessarily a good choice here.=C2=A0 Either way, i= f I were in your shoes, I'd be loading a plain text dump, maybe with so= me light massaging to strip out some compatibility issues.

Can you let us know what the hang up is?=C2=A0 Version upgrades th= ese days are usually pretty painless except for some performance issues, un= less you have some unusual situations, for example, exotic extensions.=C2= =A0

merlin



--
Regards,

#!=C2=A0 Pavan Kumar
-----------------------= ------------------------
Sr. Database Administrator..!
NEXT GENERATION = PROFESSIONALS, LLC
Cell =C2=A0 =C2=A0#=C2=A0 267-799-3182 = #=C2=A0 pavan.dba27 (Gtalk)=C2=A0=C2=A0
India =C2=A0 # 900045908= 3

Take Risks; if you win, you wil= l be very happy. If you lose you will be Wise =C2=A0
--000000000000889df706404296e4--