public inbox for [email protected]  
help / color / mirror / Atom feed
From: Raj <[email protected]>
To: Tayyab Fayyaz <[email protected]>
Cc: Laurenz Albe <[email protected]>
Cc: Pgsql-admin <[email protected]>
Subject: Re: Migration from MSSQL to POSTGRESQL
Date: Mon, 1 Dec 2025 14:07:46 +0530
Message-ID: <CAJk5AtYYmxWH6Tbp-3dAiMKd3Ynu4J6ajtOc48rKsa1s3Kk0SA@mail.gmail.com> (raw)
In-Reply-To: <CAFVRaQ2zxmVY+zqADEv2hqo9uR6Q-iYn0v2MQ2EKUtv+yRZKsA@mail.gmail.com>
References: <CAJk5AtY9E2E3tL3=1zt82LBZK7Q8BkH65BNG=43oa3qWLrPAtg@mail.gmail.com>
	<[email protected]>
	<CAFVRaQ2zxmVY+zqADEv2hqo9uR6Q-iYn0v2MQ2EKUtv+yRZKsA@mail.gmail.com>

Sorry, it's Oracle to POSTGRESQL migration.

I apologize for the confusion.

Please suggest based on Oracle.

On Mon, 1 Dec 2025, 14:00 Tayyab Fayyaz, <[email protected]> wrote:

> Hello Raj,
>
> It really depends on how much of those 64 vCPUs and 250GB RAM your SQL
> Server actually uses today, and whether you’re running on a physical box or
> a virtual machine.
>
> PostgreSQL doesn’t have a 1:1 sizing formula against SQL Server. I’d first
> look at real CPU/memory usage, workload pattern (OLTP vs reporting), and
> how connections/queries behave. I’d also factor in how well we can migrate
> and map the data types and queries, because good type choices and query
> rewrites can significantly reduce resource usage.
>
>    -
>
>    *If it’s a physical server*, I’d start with similar hardware for
>    PostgreSQL and then tune Postgres parameters (shared_buffers, work_mem,
>    etc.) based on monitoring.
>    -
>
>    *If it’s a VM*, I’d provision a bit more capacity than the current SQL
>    Server allocation to give some headroom for tuning and unexpected overhead,
>    and then right-size after observing the real load in PostgreSQL.
>
> Once the migration is done and in steady use, we can monitor CPU, memory,
> and I/O in PostgreSQL and then optimise or scale down/up based on real
> metrics instead of guessing up front.
>
>
> Tayyab
>
> On Sun, Nov 30, 2025 at 11:14 PM Laurenz Albe <[email protected]>
> wrote:
>
>> On Mon, 2025-12-01 at 08:46 +0530, Raj wrote:
>> > I am migrating from MSSQL to POSTGRESQL. In MSSQL, I am using 64 vCPU
>> and 250GB RAM.
>> > Now how much we can give in postgres?
>>
>> If these specifications worked for you with Microsoft SQL Server, use the
>> same
>> with PostgreSQL.  If you can, don't use Windows.
>>
>> Yours,
>> Laurenz Albe
>>
>>
>>


reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected], [email protected], [email protected]
  Subject: Re: Migration from MSSQL to POSTGRESQL
  In-Reply-To: <CAJk5AtYYmxWH6Tbp-3dAiMKd3Ynu4J6ajtOc48rKsa1s3Kk0SA@mail.gmail.com>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox