Migrating Data from Legacy Enterprise Data Warehouse to Cloud Platform

By Vilas Patel | @intelia | February 19

Migrating data from a legacy on-prem data warehouse to a cloud platform involves several key steps to ensure a smooth and successful transition. Here’s a breakdown of the typical steps involved:

1) Assessment:

  • Evaluate your current data warehouse: Analyse its architecture, data volume, performance, and dependencies.
  • Understand the data sources, data models, ETL processes, data quality, and performance issues.
  • Identify any dependencies or constraints that might impact the migration process.

2) Set Goals:

  • Define your cloud migration goals: Set clear objectives for the migration, focusing on specific improvements or challenges you want to address.

3) Select a cloud platform:

  • Choose a modern cloud data platform that best suits your organisation’s needs. Consider factors like scalability, cost, security, performance and compatibility with your data and tools. Popular options include Google BigQuery, Amazon Redshift, and Snowflake. Evaluate and compare these platforms to determine the best fit for your migration.

4) Define Migration Strategy:

  • Select your migration strategy depending on your needs and complexity. This could involve “lift-and-shift” where you migrate the existing infrastructure as-is to the cloud, “re-platforming,” or “rearchitecting” where you redesign the data models and ETL processes to leverage the capabilities of the cloud data platform.

5) Create a Migration Plan:

  • Develop a detailed migration plan: This plan should outline the steps, timeline, resources, and budget required for each phase of the migration.

6) Data Preparation and Cleansing:

  • Identify and remove duplicate, incomplete, or inaccurate data: Ensure data quality and consistency before migration.
  • Transform data formats: Map the data elements and entities to their corresponding counterparts in the cloud data platform. Identify any required data transformations, such as schema changes, data type conversions, or data cleansing, to ensure compatibility with the cloud platform.
  • Extract the data from your on-premise data warehouse using appropriate ETL tools or scripts.
  • Develop data migration tools or scripts: Automate as much of the data movement as possible for efficiency and accuracy.

7) Set up the Cloud Data Platform:

  • Set up and configure the chosen cloud data platform. Set up the necessary infrastructure, storage, and compute resources based on your data requirements. Configure the security measures, including access controls and encryption, to protect your data in the cloud environment. Prepare the cloud data platform to receive and process the migrated data.

8) Data Migration:

  • Choose data transfer methods: Select suitable methods based on the data volume, security needs, and cost considerations. Options include network transfers, cloud storage services, or specialised data migration tools.
  • Load the extracted and transformed data into the cloud data platform. Use the appropriate data loading mechanisms provided by the platform, such as bulk loading or streaming. Monitor the loading process to ensure its successful completion.

9) Modify ETL Processes:

  • Adapt and modify the existing ETL processes to work with the cloud data platform. Leverage the native capabilities and tools provided by the cloud platform for efficient data integration, transformation, and orchestration. Optimise the ETL workflows to take advantage of the scalability and performance benefits offered by the cloud environment.

10) Data Validation:

  • Perform comprehensive data validation and testing to ensure the migrated data in the cloud data platform matches the expected results. Validate the data consistency, integrity, and accuracy across various data dimensions. Conduct performance testing to ensure the new cloud data platform meets the desired performance benchmarks.

11) Cut over and Decommission:

  • Once the data migration is complete, plan the cut-over from the on-premise data warehouse to the cloud data platform. Redirect the necessary applications and processes to start utilising the migrated data in the cloud. Decommission the on-premise data warehouse, ensuring proper backup and archiving of the data as per compliance requirements.

12) Post-Migration Testing:

  • Perform comprehensive testing: Test data access, functionality, and performance in the cloud environment.
  • Optimise resource utilisation: Configure your cloud environment for optimal performance and cost efficiency.
  • Monitor and maintain: Continuously monitor performance, implement necessary security measures, and adjust the cloud environment as needed.

Additional Considerations:

  • Security and compliance: Ensure data security and adhere to relevant regulations throughout the migration process.
  • Change management: Communicate effectively with stakeholders and provide training to manage expectations and adoption.
  • Cost optimisation: Monitor and manage cloud costs effectively to stay within the budget.


By following these steps and considering the additional points, you can increase your chances of a successful and efficient data migration from your legacy warehouse to the cloud platform.

intelia are experts in all things data, including migrations so reach out to us if you would like to find out more about how we can help you in this space.