Babelfish: Frequently asked questions

This page contains some of the most frequently asked question related to Babelfish- and Microsoft SQL Server- compatibility.

Can we use Babelfish for free?

Yes, Babelfish can be used free of charge. It is open source software which is provided under the terms of the Apache 2.0 license and PostgreSQL license.

Is Babelfish 100% compatible with Microsoft SQL Server?

The Babelfish community tries to be as compatible as possible but there will always be some limitations. If you want to learn more about these limitations, check out our documentation which gives a more detailed description.

Babelfish supports TDS protocol versions 7.1 and higher.

Which Babelfish versions are available?

Currently we support addons to PostgreSQL 13 or higher. Support for older versions is not planned. However, there is a string commitment to support future versions of PostgreSQL as they are released.

How can I figure out which version I am running?

In Babelfish (and Microsoft SQL Server) you can make use of the @@version variable as shown in the next listing:

1> SELECT @@version;
2> GO
version                                                                                                                                                                                                                                                         
---------------------------------------------------------------------
Babelfish for PostgreSQL with SQL Server Compatibility - 12.0.2000.8
Oct 19 2021 13:21:04
Copyright (c) Amazon Web Services
PostgreSQL 13.4 on x86_64-pc-linux-gnu                                                                                              
(1 rows affected)

You can also use the following commands to figure out which versions are used:

1> SELECT SERVERPROPERTY('BabelfishVersion')
2> GO
serverproperty
1.0.0
(1 row affected)

1> SELECT SERVERPROPERTY('Babelfish')
2> GO
serverproperty
1
(1 row affected)

Can I use a database with the TDS protocol and the PostgreSQL protocol at the same time?

Yes, this is possible. A database can present itself as standard PostgreSQL and as Microsoft SQL Server (TDS protocol) at the same time.

Which TDS clients are known to work with Babelfish?

The following clients are officially supported:

• OLEDB Provider/MSOLEDBSQL
• OLEDB Driver/SQLOLEDB (deprecated)
• Ado.NET entity framework
• SQL Server Native Client 11.0 (deprecated)
• Open Database Connectivity (ODBC)
• Java Database Connectivity (JDBC)

Other tools such as FreeTDS are known to work, but are not yet officially supported.

Can Babelfish be used as an extension for PostgreSQL?

The ultimate goal is to make that happen. However, to make Babelfish work, PostgreSQL needs postgresql hooks which are currently not part of the standard version of PostgreSQL. Therefore, a special source tree of Babelfish is needed - check out our installation guide.

What is the performance difference between Microsoft SQL Server and Babelfish?

The performance difference is highly dependent on the type of query you are running. Some operations will be faster, some will be slower. There is no general answer which holds true for all cases.

How many concurrent users does Babelfish support?

There is no hard limit on the number of concurrent users, but in practice, the number of concurrent queries will be limited by the resources (CPU, I/O) of your system.

Is it possible to run T-SQL?

Yes, support for a great deal of T-SQL language is available. Here is an example:

CREATE PROCEDURE [HumanResources].[uspUpdateEmployeePersonalInfo]
    @BusinessEntityID [int], 
    @NationalIDNumber [nvarchar](15), 
    @BirthDate [datetime], 
    @MaritalStatus [nchar](1), 
    @Gender [nchar](1)
WITH EXECUTE AS CALLER
AS $$
BEGIN
    -- SET NOCOUNT ON;

    BEGIN TRY
        UPDATE [HumanResources].[Employee] 
        SET [NationalIDNumber] = @NationalIDNumber 
            ,[BirthDate] = @BirthDate 
            ,[MaritalStatus] = @MaritalStatus 
            ,[Gender] = @Gender 
        WHERE [BusinessEntityID] = @BusinessEntityID;
    END TRY
    BEGIN CATCH
        EXECUTE [dbo].[uspLogError];
    END CATCH;
END; $$ LANGUAGE 'pltsql';

Will Babelfish be available for new versions of PostgreSQL?

There are ongoing efforts to incorporate Babelfish hooks into PostgreSQL. In the meantime, a code tree with all the hooks built into it will be available separate from the extensions. This code tree will be maintained for the subsequent versions of PostgreSQL.

How can I report a bug?

To report a bug, check out the Github Babelfish Extensions repository and report your findings.

Please make sure that a test case as well as software versions and all other relevant information are included in the report, to make it easier to track down problems. In case of a crash, a gdb backtrace is highly appreciated.