Обсуждение: [MASSMAIL]Mssql to postgres migration

On Thu, Mar 28, 2024 at 1:57 PM Rajesh Kumar <rajeshkumar.dba09@gmail.com> wrote:

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 ?

What's DA?

 

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.

I'd search for an MS-SQL Foreign Data Wrapper for Postgresql.

 

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

chat with me on Signal messenger

So , is it better to have DR set up like the follows instead of multimaster?

Location1: 1 master and 1 standby

Location2: 1 standby

?

On Thu, 28 Mar 2024, 23:39 Holger Jakobs, <holger@jakobs.com> wrote:

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

chat with me on Signal messenger