Microsoft SQL Server is reliable, but licensing costs, Windows dependencies, and cloud pricing lead many teams to move to PostgreSQL. PostgreSQL offers a powerful, open-source database with strong standards support and managed options on every major cloud. The migration, though, is more than copying tables: T-SQL procedures, identity columns, date types, collations, and application queries all behave differently.
Our SQL Server to PostgreSQL migration services handle those differences end to end. We assess your databases, convert schemas and T-SQL, migrate data with minimal downtime, update application SQL, validate every table, and tune PostgreSQL so it performs well from day one.
What is SQL Server to PostgreSQL migration? SQL Server to PostgreSQL migration moves databases from Microsoft SQL Server to PostgreSQL. It involves converting schemas, data types, identity columns, and constraints, rewriting T-SQL stored procedures, functions, and triggers into PL/pgSQL, migrating data with tools such as AWS DMS, pgloader, or custom scripts, keeping data synchronized until cutover, updating application queries and connection settings, validating results, and tuning performance on PostgreSQL.
SQL Server to PostgreSQL Migration at a Glance
Question | Answer |
|---|---|
What it is | Moving SQL Server databases, code, and data to PostgreSQL with minimal downtime |
Core deliverables | Migration assessment, converted schemas and PL/pgSQL, migrated and synchronized data, updated application SQL, validation reports, performance tuning |
Targets | Self-managed PostgreSQL, Amazon RDS, Aurora PostgreSQL, Azure Database for PostgreSQL, Google Cloud SQL, AlloyDB |
Tools | AWS Schema Conversion Tool and DMS, pgloader, Babelfish for Aurora PostgreSQL (where suitable), custom scripts |
Downtime approach | Bulk load plus change data capture for a short cutover window |
Engagement models | Migration assessment, full migration project, post-migration optimization |
Why Migrate From SQL Server to PostgreSQL
Lower licensing costs — PostgreSQL has no per-core license fees
Platform freedom — runs on Linux, containers, and every major cloud
Strong features — JSONB, advanced indexing, extensions such as PostGIS and pgvector
Standards compliance — closer alignment with ANSI SQL
Wide talent pool — PostgreSQL skills are widely available
Key Conversion Differences
SQL Server | PostgreSQL | What we do |
|---|---|---|
T-SQL procedures and functions | PL/pgSQL functions and procedures | Rewrite logic and test results |
IDENTITY columns | Identity columns or sequences | Convert and preserve current values |
DATETIME, NVARCHAR, BIT, UNIQUEIDENTIFIER | TIMESTAMP, VARCHAR or TEXT, BOOLEAN, UUID | Map each column to the right type |
TOP, ISNULL, GETDATE() | LIMIT, COALESCE, NOW() | Rewrite queries |
Case-insensitive default collation | Case-sensitive by default | Handle with citext, collations, or query changes |
Temp tables and table variables | Temporary tables, CTEs | Redesign where behavior differs |
SQL Server Agent jobs | pg_cron, cloud schedulers, or orchestration tools | Recreate scheduled jobs |
Case sensitivity and T-SQL behavior are the most common sources of subtle bugs, so we test them carefully.
Our SQL Server to PostgreSQL Services
Migration assessment
We inventory databases, objects, T-SQL code, jobs, linked servers, and connected applications, run automated compatibility analysis, and estimate effort and risk.
Schema conversion
We convert tables, data types, constraints, indexes, views, and identity columns.
T-SQL to PL/pgSQL conversion
We rewrite stored procedures, functions, and triggers, and test that results match.
Application changes
We update application SQL, ORM settings, connection strings, and drivers, and test applications against PostgreSQL.
Babelfish evaluation
For AWS targets, we assess whether Babelfish for Aurora PostgreSQL can reduce application changes, and where full conversion is the better choice.
Data migration and sync
We bulk-load data, then keep PostgreSQL synchronized with change data capture until cutover.
Validation
We compare row counts, checksums, and samples for every table, and run application and report tests.
Jobs and integrations
We recreate SQL Server Agent jobs, SSIS packages, and integrations using PostgreSQL-compatible tools.
Performance tuning
We tune indexes, queries, configuration, and connection pooling for your workloads.
How It Works
Step 1: Assess
We analyze your SQL Server estate and produce an effort, risk, and cost estimate.
Step 2: Convert
We convert schemas, code, and jobs, and test them against copies of your data.
Step 3: Migrate and sync
We load data and keep it synchronized.
Step 4: Test
We validate data and run application, report, and performance tests.
Step 5: Cut over
We switch applications to PostgreSQL in a short, rehearsed window.
Step 6: Optimize and retire
We tune the new database and help decommission SQL Server.
What You Get
A detailed migration assessment
Converted, tested schemas and PL/pgSQL code
Updated application SQL and connections
Migrated, synchronized, validated data
Recreated jobs and integrations
A rehearsed cutover and performance tuning
Who This Is For
Companies cutting license costs | SaaS products | Teams moving to the cloud | Teams leaving Windows servers |
|---|---|---|---|
Want to reduce SQL Server licensing | Want a portable, open-source database for their product | Want managed PostgreSQL on AWS, Azure, or Google Cloud | Want Linux and container-friendly infrastructure |
Why Work With Codersarts
SQL Server to PostgreSQL migrations look simple until collations, T-SQL behavior, and application queries surface. We find these early with automated analysis and careful review, test thoroughly, and keep SQL Server available until PostgreSQL is proven. The work follows our database migration process, and our SQL query specialists tune performance after the move.
Frequently Asked Questions
How long does a SQL Server to PostgreSQL migration take?
Small databases with little T-SQL can move in a few weeks. Larger systems with many procedures, jobs, and applications typically take several weeks to a few months.
Can tools convert T-SQL automatically?
Tools convert much of the schema and some code. Complex procedures, dynamic SQL, and application queries usually need manual conversion and testing.
What is Babelfish?
Babelfish for Aurora PostgreSQL lets Aurora PostgreSQL understand much of SQL Server's T-SQL and wire protocol, which can reduce application changes. It doesn't support every feature, so we assess fit before recommending it.
How do you handle case-insensitive searches?
PostgreSQL is case-sensitive by default. We use the citext type, nondeterministic collations, or query changes to preserve expected behavior.
Can we migrate with minimal downtime?
Yes. We bulk-load data and keep it synchronized with change data capture, so the final switch takes a short window.
What happens to SSIS packages and Agent jobs?
We recreate them with PostgreSQL-compatible tools such as pg_cron, cloud schedulers, Airflow, or modern ETL pipelines.
How much does SQL Server to PostgreSQL migration cost?
Cost depends on database size, T-SQL volume, applications, jobs, and downtime requirements. The assessment provides a detailed estimate.
Related Data Services
Oracle to PostgreSQL Migration — the same approach for Oracle databases
Azure Data Services — Azure Database for PostgreSQL and the wider Azure platform
Database Design & Architecture — improve structure during the move
Airflow Consulting — replace Agent jobs and SSIS with orchestrated pipelines
Ready to Move From SQL Server to PostgreSQL?
Tell us about your SQL Server databases and the applications that use them. We'll assess the effort and show you what the migration would take.
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