# mssql > Babelfish template pinned to a PostgreSQL 17-compatible kernel with SQL Server protocol and T-SQL support --- LLMS index: [llms.txt](/llms.txt) --- The `mssql` configuration template uses a **PostgreSQL 17-compatible Babelfish** kernel instead of native PostgreSQL, providing Microsoft SQL Server wire protocol (TDS) and T-SQL syntax compatibility. The current template is pinned to `pg_version: 17`; `configure` does not apply `-v` overrides to this fixed-kernel template. Since Pigsty v4.2, Babelfish is built directly by Pigsty, no longer using the WiltonDB repository, and is available on all [supported Linux platforms](/docs/ref/linux). For the complete tutorial, see: **[Babelfish (MSSQL) Kernel Guide](/docs/pgsql/kernel/babelfish/)** -------- ## Overview - Config Name: `mssql` - Node Count: Single node - Description: Babelfish (PG17) configuration template with SQL Server protocol compatibility - OS Distro: `el8`, `el9`, `el10`, `d12`, `d13`, `u22`, `u24`, `u26` - OS Arch: `x86_64`, `aarch64` - Related: [`meta`](/docs/conf/meta/) Usage: ```bash ./configure -c mssql [-i ] ``` -------- ## Content Source: [`pigsty/conf/mssql.yml`](https://github.com/pgsty/pigsty/blob/main/conf/mssql.yml) ```yaml --- #==============================================================# # File : mssql.yml # Desc : Babelfish (MSSQL Wire-Compatible) template # Ctime : 2020-08-01 # Mtime : 2026-07-08 # Docs : https://pigsty.io/docs/conf/mssql # License : Apache-2.0 @ https://pigsty.io/docs/about/license/ # Copyright : 2018-2026 Ruohang Feng / Vonng (rh@vonng.com) #==============================================================# # This is the config template for Babelfish Kernel made by Pigsty # Which is a PostgreSQL 17/18 fork with SQL Server Compatibility # tutorial: https://pigsty.io/docs/pgsql/kernel/babelfish # # Usage: # curl https://repo.pigsty.io/get | bash # ./configure -c mssql [-v 17/18] # ./deploy.yml all: children: infra: { hosts: { 10.10.10.10: { infra_seq: 1 }} ,vars: { repo_enabled: false }} etcd: { hosts: { 10.10.10.10: { etcd_seq: 1 }} ,vars: { etcd_cluster: etcd }} #minio: { hosts: { 10.10.10.10: { minio_seq: 1 }} ,vars: { minio_cluster: minio }} #----------------------------------------------# # Babelfish Database Cluster #----------------------------------------------# pg-meta: hosts: 10.10.10.10: { pg_seq: 1, pg_role: primary } vars: pg_cluster: pg-meta pg_users: - {name: dbuser_mssql ,password: DBUser.MSSQL ,superuser: true, pgbouncer: true ,roles: [dbrole_admin], comment: superuser & owner for babelfish } pg_databases: - name: mssql baseline: mssql.sql extensions: [uuid-ossp, babelfishpg_common, babelfishpg_tsql, babelfishpg_tds, babelfishpg_money ] owner: dbuser_mssql parameters: { 'babelfishpg_tsql.migration_mode' : 'multi-db' } comment: babelfish cluster, a MSSQL compatible pg cluster pg_crontab: # https://pigsty.io/docs/pgsql/admin/crontab - '00 01 * * * /pg/bin/pg-backup full' # Babelfish Ad Hoc Settings pg_mode: mssql # Microsoft SQL Server Compatible Mode pg_version: 17 pg_packages: [ babelfish, pgsql-common, sqlcmd ] pg_libs: 'babelfishpg_tds, pg_stat_statements, auto_explain' # preload Babelfish TDS listener pg_hba_rules: # https://pigsty.io/docs/pgsql/config/hba - { user: dbuser_mssql ,db: mssql ,addr: intra ,auth: md5 ,title: 'allow mssql dbsu intranet access' ,order: 525 } # <--- use md5 auth method for mssql user - { user: all ,db: all ,addr: intra ,auth: md5 ,title: 'everyone intranet access with md5 pwd' ,order: 800 } pg_default_services: # route primary & replica service to mssql port 1433 - { name: primary ,port: 5433 ,dest: 1433 ,check: /primary ,selector: "[]" } - { name: replica ,port: 5434 ,dest: 1433 ,check: /read-only ,selector: "[]" , backup: "[? pg_role == `primary` || pg_role == `offline` ]" } - { name: default ,port: 5436 ,dest: postgres ,check: /primary ,selector: "[]" } - { name: offline ,port: 5438 ,dest: postgres ,check: /replica ,selector: "[? pg_role == `offline` || pg_offline_query ]" , backup: "[? pg_role == `replica` && !pg_offline_query]" } vars: #----------------------------------------------# # INFRA : https://pigsty.io/docs/infra/param #----------------------------------------------# version: v4.5.0 # pigsty version string admin_ip: 10.10.10.10 # admin node ip address region: default # upstream mirror region: default,china,europe infra_portal: # infra services exposed via portal home : { domain: i.pigsty } # default domain name #----------------------------------------------# # NODE : https://pigsty.io/docs/node/param #----------------------------------------------# nodename_overwrite: false # do not overwrite node hostname on single node mode node_repo_modules: node,infra,pgsql # babelfish kernel is in the pgsql repo node_tune: oltp # node tuning specs: oltp,olap,tiny,crit #----------------------------------------------# # PGSQL : https://pigsty.io/docs/pgsql/param #----------------------------------------------# pg_version: 17 # Babelfish kernel is compatible with postgres 17 pg_conf: oltp.yml # pgsql tuning specs: {oltp,olap,tiny,crit}.yml #----------------------------------------------# # PASSWORD : https://pigsty.io/docs/setup/security/ #----------------------------------------------# grafana_admin_password: pigsty grafana_view_password: DBUser.Viewer pg_admin_password: DBUser.DBA pg_monitor_password: DBUser.Monitor pg_replication_password: DBUser.Replicator patroni_password: Patroni.API haproxy_admin_password: pigsty minio_secret_key: S3User.MinIO etcd_root_password: Etcd.Root ... ``` -------- ## Explanation The `mssql` template allows you to use SQL Server Management Studio (SSMS) or other SQL Server client tools to connect to PostgreSQL (through Babelfish protocol compatibility). **Key Features**: - Uses TDS protocol (port 1433), compatible with SQL Server clients - Supports T-SQL syntax, low migration cost - Retains PostgreSQL's ACID properties and extension ecosystem (the current template uses PG17) - Supports `multi-db` and `single-db` migration modes - Default package set: `babelfish + pgsql-common + sqlcmd` - Creates `uuid-ossp`, `babelfishpg_common`, `babelfishpg_tsql`, `babelfishpg_tds`, and `babelfishpg_money` by default - v4.2.0 adds full mainstream platform coverage (EL 8/9/10, Debian 12/13, Ubuntu 22/24/26; `x86_64` / `aarch64`) **Connection Methods**: ```bash # Using sqlcmd command line tool sqlcmd -S 10.10.10.10,1433 -U dbuser_mssql -P DBUser.MSSQL -d mssql # Using SSMS or Azure Data Studio # Server: 10.10.10.10,1433 # Authentication: SQL Server Authentication # Login: dbuser_mssql # Password: DBUser.MSSQL ``` **Use Cases**: - Migrating from SQL Server to PostgreSQL - Applications needing to support both SQL Server and PostgreSQL clients - Leveraging PostgreSQL ecosystem while maintaining T-SQL compatibility **Notes**: - The current `mssql` template is pinned to a PostgreSQL 17-compatible kernel; do not rely on `-v` to switch its major version - Default migration mode is `multi-db` (`babelfishpg_tsql.migration_mode`), configurable to `single-db` when needed - Some T-SQL syntax may have compatibility differences, refer to Babelfish compatibility documentation - Must use `md5` authentication method (not `scram-sha-256`)