babelfishpg_tsql

babelfish : SQL Server Transact SQL compatibility

Overview

Packages

Source

pig build pkg babelfish;		# build rpm/deb

Install

Make sure PGDG and PIGSTY repo available:

pig repo add pgsql -u   # add both repo and update cache

Install this extension with pig:

pig install babelfish;		# install via package name, for the active PG version
pig install babelfishpg_tsql;		# install by extension name, for the current active PG version

pig install babelfishpg_tsql -v 18;   # install for PG 18
pig install babelfishpg_tsql -v 17;   # install for PG 17

Create this extension with:

CREATE EXTENSION babelfishpg_tsql CASCADE; -- requires babelfishpg_common, uuid-ossp

Usage

Sources:

• Babelfish extensions BABEL_5_4_0 README
• Installation guide
• babelfishpg_tsql control file
• Babelfish limitations
• Handling T-SQL

babelfishpg_tsql implements the T-SQL language and SQL Server-compatible catalog behavior used by Babelfish. It is one component of a Babelfish database, not a compatibility layer that can be added to stock PostgreSQL by itself: the complete stack requires the Babelfish-patched PostgreSQL engine plus the common, TDS, and T-SQL extensions.

Core Workflow

Configure the TDS protocol extension for preload and restart the Babelfish server:

shared_preload_libraries = 'babelfishpg_tds'

Create the TDS extension with CASCADE so its extension dependencies, including babelfishpg_tsql, are installed. Choose the migration mode before initialization.

CREATE EXTENSION IF NOT EXISTS babelfishpg_tds CASCADE;

ALTER SYSTEM SET babelfishpg_tsql.database_name = 'babelfish_db';
ALTER SYSTEM SET babelfishpg_tsql.migration_mode = 'multi-db';

CALL sys.initialize_babelfish('babelfish_user');

After configuration is reloaded as directed by the installation guide, SQL Server clients connect to the TDS listener, commonly on port 1433, and issue T-SQL in the logical databases created by Babelfish.

Component and Object Index

• babelfishpg_tsql supplies the T-SQL parser, procedural language, system objects, compatibility functions, and T-SQL configuration variables.
• babelfishpg_tds supplies the Tabular Data Stream listener and is the normal installation entry point.
• babelfishpg_common supplies shared data types and functions. It and uuid-ossp are declared dependencies of babelfishpg_tsql.
• babelfishpg_money supplies money-related compatibility objects used by the stack.
• sys.initialize_babelfish(login_name) provisions the Babelfish catalogs and initial login.
• sys.sp_babelfish_configure controls documented compatibility escape hatches.
• babelfishpg_tsql.database_name identifies the physical PostgreSQL database hosting Babelfish.
• babelfishpg_tsql.migration_mode selects single-db or multi-db logical-database mapping.

Operational Boundaries

Installation requires superuser privileges and a Babelfish build matched to the extension release. Do not install babelfishpg_tsql alone and expect TDS connectivity. The migration mode is a provisioning decision and is not intended to be changed after the database is initialized.

Babelfish implements a substantial but incomplete SQL Server surface. Validate application syntax, data types, system-catalog assumptions, drivers, and escape-hatch settings against the official limitations before migration. PostgreSQL and T-SQL connections can observe different naming and transaction semantics.

The catalog change from 5.5.0 to 5.4.0 is a version correction to the official BABEL_5_4_0 release line, not evidence of a new feature or an automatic downgrade procedure.