From: Holger Jakobs <holger@jakobs.com>
To: pgsql-admin@lists.postgresql.org
Subject: Re: Mssql to postgres migration
Date: Thu, 28 Mar 2024 19:08:53 +0100
Message-ID: <c0c3d835-93e3-aeb7-34df-eaadfd8d507a@jakobs.com> (raw)
In-Reply-To: <CAJk5AtYUsVs4pybZ-s3NE435dQauu2XWQAjeDjHus4+WE-kcoQ@mail.gmail.com>
References: <CAJk5AtYUsVs4pybZ-s3NE435dQauu2XWQAjeDjHus4+WE-kcoQ@mail.gmail.com>
Am 28.03.24 um 18:57 schrieb Rajesh Kumar:
> Hi
>
> Is it possible to migrate from mssql to postgres?
>
> Any links available?
>
> Can I setup postgres DA like location1: 1 master and 1 slave and
> location2: 1 master and 1 slave ?
>
>
> Is there a better way to set up DA?
>
> I am very very new to these topics..I have searched enough in
> internet. Could not find the right source.
Yes, of course a migration is possible. Any migration is.
Unfortunately, there are less tools available compared to the migration
from Oracle. Just have a look at the foreign data wrappers for these
systems. The Oracle FDW is well maintained, documented and has many
features. The MS SQL FDW is old, not well documented and is lacking many
features. It can't even write or push down anything.
Some tool that might help are:
* pgLoader
* sqlserver2pgsql
M$ people like to call the product "Microsoft SQL Server" just "SQL
Server", as if it was THE SQL Server and PostgreSQL, Oracle or DB2
weren't SQL Servers.
There is a Schema Conversion Tool by AWS in case you want to migrate to
PostgreSQL on AWS. Maybe it's possible to go this way and then continue
to on-premise PostgreSQL.
With PostgreSQL you always have 1 Primary (formerly called Master) and
any number of Secondaries (formerly called Slaves). So no, you cannot
have two Primaries, whether in a single or in two separate locations.
Keeping several Primaries completely in Sync and continuously
maintaining ACID makes everything so slow that it is hardly a sensible
solution.
"Multi-Master" promises a lot, but keeps little.
Kind Regards,
Holger
--
Holger Jakobs, Bergisch Gladbach, Tel. +49-178-9759012
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Subject: Re: Mssql to postgres migration
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