Migrating an SQL Server database to AWS RDS Aurora PostgreSQL

 Migrating an SQL Server database to AWS RDS Aurora PostgreSQL 

Step 1: Planning

  1. Assess the Migration: Evaluate the source SQL Server database and identify any potential issues. Consider schema differences, data types, and compatibility issues.
  2. Backup Strategy: Plan for a backup strategy to ensure you have a point-in-time restore option.
  3. Tools and Resources: Familiarize yourself with AWS Database Migration Service (DMS) and AWS Schema Conversion Tool (SCT).

Step 2: Set Up AWS Environment

  1. Create an AWS Account: If you don’t already have one, create an AWS account.
  2. Set Up IAM Roles and Policies: Ensure you have the necessary IAM roles and policies to manage AWS services securely.
  3. Launch Aurora PostgreSQL Instance:
    • Go to the RDS console.
    • Select "Create Database".
    • Choose "Amazon Aurora".
    • Select "PostgreSQL-compatible".
    • Configure the instance size, storage, and other settings.
    • Launch the instance.

Step 3: Schema Conversion

  1. Install AWS SCT:
    • Download and install the AWS Schema Conversion Tool from the AWS website.
  2. Connect to Source SQL Server:
    • Open AWS SCT.
    • Connect to your SQL Server database by providing the connection details.
  3. Connect to Target Aurora PostgreSQL:
    • Connect to your Aurora PostgreSQL instance.
  4. Convert the Schema:
    • Use AWS SCT to convert the SQL Server schema to PostgreSQL-compatible schema.
    • Review and apply any necessary modifications manually.
    • Apply the converted schema to the Aurora PostgreSQL instance.

Step 4: Data Migration

  1. Install AWS DMS:
    • Go to the AWS DMS console.
    • Create a replication instance.
    • Ensure the replication instance can connect to both the source SQL Server and target Aurora PostgreSQL.
  2. Create Endpoints:
    • Create source endpoint for SQL Server.
    • Create target endpoint for Aurora PostgreSQL.
  3. Create a Migration Task:
    • Define a migration task in AWS DMS.
    • Choose the type of migration (full load, full load + CDC, or CDC only).
  4. Run the Migration Task:
    • Start the migration task.
    • Monitor the migration process using the DMS console.
    • Validate data after the migration task completes.

Step 5: Post-Migration

  1. Data Validation:
    • Compare the data in the source SQL Server and target Aurora PostgreSQL to ensure completeness and accuracy.
  2. Application Testing:
    • Test your applications with the new Aurora PostgreSQL database to ensure they work as expected.
  3. Performance Tuning:
    • Optimize your PostgreSQL database settings for better performance.
    • Apply necessary indexing and query optimizations.

Step 6: Cutover

  1. Plan for Downtime:
    • Schedule a maintenance window for the cutover to minimize impact.
  2. Final Data Sync:
    • Perform a final data sync if using CDC (Change Data Capture) to ensure no data is missed.
  3. Switch Applications:
    • Update your application configurations to point to the new Aurora PostgreSQL database.
  4. Monitor:
    • Monitor the applications and database closely after cutover to quickly address any issues.

Step 7: Decommission

  1. Decommission Old SQL Server:
    • Once confirmed that the new system is working perfectly, decommission the old SQL Server database.
  2. Cleanup:
    • Remove any unused resources in AWS to avoid unnecessary costs.


Migrating from SQL Server to AWS RDS Aurora PostgreSQL requires careful planning and execution. Using tools like AWS SCT and AWS DMS can simplify the process, but manual intervention and thorough testing are crucial to ensure a smooth transition.