SQL Server (Babelfish)

Babelfish for PostgreSQL provides SQL Server wire-protocol compatibility, letting you connect SQL Server clients and run T-SQL queries without modifying your application.

Connecting

Two ports are available:

Port	Protocol	Client
1433	TDS (SQL Server wire)	SQL Server drivers, SSMS, sqlcmd
5432	PostgreSQL	psql, JDBC, all PostgreSQL clients

SQL Server clients

# sqlcmd
sqlcmd -S HOST,1433 -U USER -P PASS -Q "SELECT @@VERSION"

# Connection string (.NET / ADO.NET)
Server=HOST,1433;Database=defaultdb;User Id=USER;Password=PASS;Encrypt=true;TrustServerCertificate=false;

# JDBC (SQL Server driver)
jdbc:sqlserver://HOST:1433;databaseName=defaultdb;user=USER;password=PASS;encrypt=true;

PostgreSQL clients

PGPASSWORD=PASS psql "host=HOST user=USER dbname=defaultdb sslmode=verify-full"

T-SQL Compatibility

Babelfish supports a large subset of T-SQL syntax including:

• SELECT, INSERT, UPDATE, DELETE, MERGE
• Stored procedures (CREATE PROCEDURE)
• Functions (CREATE FUNCTION)
• Triggers (CREATE TRIGGER)
• SQL Server data types (NVARCHAR, DATETIME, UNIQUEIDENTIFIER, BIT, etc.)
• sys. catalog views (partial emulation)
• INFORMATION_SCHEMA views
• SET options (NOCOUNT, ANSI_NULLS, etc.)

Known Limitations

Not all SQL Server features are supported. Common gaps:

Feature	Status
SQL Server Agent jobs	Not supported
Linked servers	Not supported
CLR integration	Not supported
Full-text search	Not supported
OPENROWSET / OPENDATASOURCE	Not supported
Distributed transactions (MSDTC)	Not supported
Change Data Capture (CDC)	Not supported
FOR XML clauses	Limited support
Spatial data types	Limited support

For the full compatibility matrix, see the Babelfish documentation.

Database Users

Create a user with SQL Server-compatible credentials:

curl -u admin:password -X POST \
  https://api.foundrydb.com/managed-services/{id}/database-users \
  -H "Content-Type: application/json" \
  -d '{"username": "app_user", "role": "admin"}'

Configuration

Babelfish runs on top of PostgreSQL. PostgreSQL-level tuning applies:

curl -u admin:password -X PATCH \
  https://api.foundrydb.com/managed-services/{id}/configuration \
  -H "Content-Type: application/json" \
  -d '{
    "parameters": {
      "max_connections": "200",
      "shared_buffers": "2GB"
    }
  }'

Backups

Backups use pgBackRest on the underlying PostgreSQL instance. PITR is available to any second within the retention window:

curl -u admin:password -X POST \
  https://api.foundrydb.com/managed-services/{id}/backups/restore \
  -H "Content-Type: application/json" \
  -d '{"restore_point": "2026-03-15T14:30:00Z", "target_service_name": "restored-mssql"}'