11 Steps for an Effective Data Warehouse Migration

Updated November 21st, 2023
data warehouse migration

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Data warehouse migration is akin to moving your business intelligence ‘brain center’ from one environment to another.

Whether you’re scaling up, adopting more modern technology, or seeking better performance and security, the migration process is a pivotal turning point that holds the promise of transformative gains.

Done right, it streamlines operations, enables more robust data analytics, and opens doors to new capabilities that can drive your business forward.


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However, this transition also comes with its share of challenges, making it crucial to navigate with precision, expertise, and a well-laid-out plan. In essence, data warehouse migration is not just a technical shift—it’s a strategic business move.

In this article, let’s dive into the various aspects of data warehouse migration in detail.


Table of contents

  1. What is data warehouse migration? 5 Best practices to know
  2. 11 Steps for a successful data warehouse migration
  3. Types of data warehouse migration
  4. Top 10 challenges of data warehouse migration
  5. Data warehouse migration to the cloud
  6. Data warehouse migration utilities
  7. Data warehouse migration tools
  8. Bottom line
  9. Data warehouse migration: Related reads

What is data warehouse migration? 5 Best practices to know

Data warehouse migration is the process of transferring data, schema, and other components from one data warehouse environment to another.

This can involve moving from an on-premises solution to a cloud-based system, upgrading to a more advanced platform, or simply changing vendors.

The migration aims to preserve data integrity, minimize downtime, and ensure that all data and functionalities are available in the new environment as they were in the original one.

With that being said, let’s look at the top best practices for data warehouse migration.

5 Best practices for data warehouse migration


They are:

  1. Assessment and planning
  2. Backup everything
  3. Choose the right tools
  4. Test thoroughly
  5. Monitor after migration

Let’s understand each of them in detail.

1. Assessment and planning

Begin with a thorough assessment of the current environment. This helps in understanding the scope, potential risks, and determining the migration strategy.

Understand why migration is needed. Is it for scaling, cost savings, better performance, or new features.

2. Backup everything

Before starting, always create a comprehensive backup to prevent data loss.

Before starting the migration, take a full backup of the entire data warehouse. This includes data, schema, stored procedures, functions, views, and any associated metadata.

Keep records of what was backed up, the tools or methods used, the date and time, and any other pertinent details.

3. Choose the right tools

There are specialized tools available that can facilitate migration. They can automate many tasks, reduce manual errors, and speed up the process.

The choice often depends on the source and target data warehouses, the complexity of the data, and any transformation requirements.

4. Test thoroughly

Once the migration is done, it’s essential to test the new environment thoroughly to ensure all data is accurate and all functionalities work as expected.

Ensure that data access permissions are correctly migrated and validate that the new system complies with relevant data regulations (like GDPR, CCPA).

Plan for downtime: Inform stakeholders about potential downtime well in advance. If possible, schedule migrations during off-peak hours.

5. Monitor after migration

Keep a close watch on the new environment for any potential issues or discrepancies that might arise post-migration.

Post-migration monitoring is essential to ensure data integrity, performance, and the overall success of the migration process.

And post-migration monitoring isn’t just a short-term activity. Continual monitoring is crucial as workloads can change, data volumes can grow, and system performance can evolve over time.

Implementing best practices in data warehouse migration is crucial as they ensure a smooth transition, minimize risks, and maximize the benefits of the migration process, ultimately leading to improved data integrity, reduced downtime, and enhanced business performance.


11 Steps for a successful data warehouse migration

Data warehouse migration is a critical operation, necessitating detailed planning to ensure seamless transition, data integrity, and minimal disruption.

Here are the 11 steps for a successful data warehouse migration:

  1. Project initiation
  2. Assessment and inventory
  3. Migration strategy
  4. Design and architecture
  5. Migration preparation
  6. Data migration
  7. Application and process migration
  8. Testing and validation
  9. Deployment and go live
  10. Documentation and training
  11. Review and optimization

Here’s a detailed look into a successful data warehouse migration.

1. Project initiation


Identify key stakeholders, including IT leaders, business users, and data scientists. Ensure alignment on the project’s objectives, scope, and desired outcomes.

Clearly outline what the migration aims to achieve, whether it’s cost-saving, performance improvement, or accessing new features.

Identify potential risks associated with the migration and develop mitigation strategies.

2. Assessment and inventory


Document the architecture, data models, and volume of the current data warehouse. Identify all systems, applications, and processes that interact with the current data warehouse.

List the tools and technologies currently in use, and whether they’re compatible with the target environment.

3. Migration strategy


Decide on the type of migration (e.g., on-premises to cloud, cloud to cloud, legacy to modern, or hybrid).

Determine whether the migration will be a big bang (all at once) or phased. For large datasets, consider strategies like direct data transfer services or even shipping physical storage devices.

4. Design and architecture


Design the structure of the new data warehouse, considering scalability, resilience, and performance. Decide on the data modeling approach for the new environment.

Ensure robust security mechanisms, including encryption, access controls, and monitoring.

5. Migration preparation


Choose tools for data extraction, transformation, and loading (ETL). Some migrations might benefit from specialized migration tools.

Prepare the target environment, ensuring necessary storage, compute resources, and network configurations are in place. Conduct a pilot migration with a subset of data to identify potential issues and test the effectiveness of the migration process.

6. Data migration


Extract data from the source system. Convert data to the desired format or structure for the target system.

Load transformed data into the new data warehouse. Ensure data integrity, accuracy, and completeness in the new environment.

7. Application and process migration


Adjust systems, applications, or processes that depend on the old data warehouse to work with the new system.

Test integrations to ensure seamless data flow and functionality between interconnected systems.

8. Testing and validation


Compare the performance of common queries and operations in the new environment to benchmarks or the old system.

Engage end-users to test and validate that the new system meets their requirements.

9. Deployment and go-live


Determine how to switch from the old system to the new system, considering potential downtime or data synchronization needs.

Activate the new data warehouse and retire or decommission the old system. Monitor the new system closely for any issues or discrepancies.

10. Documentation and training


Create comprehensive documentation detailing the new system’s architecture, data models, processes, and best practices. Offer training sessions to IT teams, data scientists, and end-users to familiarize them with the new environment.

11. Review and optimization


Continually monitor and tweak the new system for optimal performance. Gather feedback from stakeholders to identify any areas of improvement or unmet needs.

In short, a successful data warehouse migration hinges on meticulous planning, stakeholder involvement, and rigorous testing. A well-structured project plan, such as the one above, serves as the backbone of this endeavor, guiding teams through each phase and ensuring the new data environment aligns with organizational needs.


4 Fundamental types of data warehouse migration

There are basically four types of data warehouse migration. They are:

  1. On-premise to cloud migration
  2. Cloud to cloud migration
  3. Legacy system to modern system migration
  4. Hybrid migration

Let us understand each of them in detail:

1. On-premises to cloud migration


As organizations seek flexibility, scalability, and reduced infrastructure costs, many opt to move their on-premises data warehouses to cloud platforms.

Although cloud migrations can lead to reduced infrastructure costs in the long run, there are upfront costs related to the migration process itself.

Large datasets can take significant time to transfer over the internet. Solutions might include direct data transfer services provided by cloud providers. Ensure data is encrypted during transit and at rest in the cloud.

On-premises systems and applications might require integration with the cloud platform. Many cloud platforms offer advanced analytics, AI, and machine learning integrations.

2. Cloud-to-cloud migration


This involves moving from one cloud data warehouse provider to another. This can be driven by cost factors, performance issues, or specific features offered by a different provider.

Planning to minimize downtime during the transition is critical. Data schemas, structures, and formats might differ across cloud providers and some of them may charge for data going out of their platforms.

The target cloud platform might offer better performance for specific workloads. Access to unique features or tools offered by the target platform.

3. Legacy system to modern system migration


This is the process of moving from older data warehouse systems to newer, modern architectures, whether on-premises or in the cloud.

Legacy systems might use outdated data formats or structures that need transformation. The team might need training to use and manage the new system. Legacy applications might need updates or replacements to work with the modern system.

Modern systems are typically faster and more efficient. Legacy systems often have limited support or updates, so moving to a modern system ensures continued vendor support. Access to contemporary analytics, data processing, and other features.

4. Hybrid migration


Hybrid migration involves maintaining both on-premises and cloud environments. It’s a middle ground for organizations that want the benefits of the cloud while retaining some data or applications on-premises.

Ensuring data consistency across on-premises and cloud platforms. A robust network is essential to maintain seamless communication between environments.

Implementing consistent security measures across both environments. Combining the benefits of both on-premises and cloud architectures. Keeping sensitive or frequently accessed data on-premises while leveraging the cloud for scalability and other features.

The type of data warehouse migration chosen by an organization depends on its specific needs, infrastructure, budget, and long-term vision. Regardless of the type, careful planning, testing, and monitoring are crucial to ensure a successful migration.


Top 10 challenges of data warehouse migration

Data warehouse migration involves moving data from one system to another, typically for reasons like upgrading technology, improving performance, or consolidating systems. This process can be complex and challenging due to several factors:

  1. Volume and complexity of data
  2. Data integrity and quality
  3. System downtime and business continuity
  4. Technical compatibility and integration
  5. Security and compliance
  6. Resource and cost management
  7. Change management and training
  8. Performance optimization post-migration
  9. Data synchronization
  10. Testing and validation

Let us understand each of them in detail.

1. Volume and complexity of data


  • Large data volumes: Data warehouses often contain massive volumes of data. Migrating such quantities without causing significant downtime or data loss is challenging.
  • Data complexity: Data in warehouses can be structured, semi-structured, or unstructured, with complex relationships. Ensuring all this data is correctly migrated requires careful planning.

2. Data integrity and quality


  • Maintaining data integrity: Ensuring that data remains accurate and consistent during and after the migration is crucial. This includes preserving relationships between data sets.
  • Data quality issues: Existing issues in the source system, like duplicates or incomplete data, can complicate migration. Cleaning data before migration may be necessary.

3. System downtime and business continuity


  • Minimizing downtime: Migrating a data warehouse often requires some system downtime, which can disrupt business operations.
  • Ensuring business continuity: Developing a strategy that ensures business operations can continue with minimal impact during migration is a significant challenge.

4. Technical compatibility and integration


  • Compatibility issues: Differences in database structures, data formats, and platforms between the old and new systems can create technical challenges.
  • Integration with existing systems: Ensuring the new system integrates smoothly with existing applications and systems is critical.

5. Security and compliance


  • Data security: Protecting sensitive data during the migration process is vital to prevent data breaches.
  • Regulatory compliance: Adhering to data protection regulations (like GDPR) during the migration process is necessary and can be complex.

6. Resource and cost management


  • Resource intensive: Significant human and technical resources are required, which can be costly.
  • Budget constraints: Balancing the cost of migration with its benefits is a key challenge, especially for larger migrations.

7. Change management and training


  • User training: End-users may require training on the new system.
  • Change management: Managing the change in business processes and workflows that may result from the new data warehouse system.

8. Performance optimization post-migration


  • Ensuring performance gains: One of the goals of migration is often performance improvement, which requires careful planning and optimization post-migration.

9. Data synchronization


  • Keeping data synchronized: During the transition phase, it’s crucial to keep data in both old and new systems synchronized to avoid data loss or discrepancies.

10. Testing and validation


  • Extensive testing: Rigorous testing is needed to ensure the new system works as intended.
  • Validation: Validating that all data has been accurately and completely migrated is essential.

Each of these challenges requires careful planning and execution to ensure a successful data warehouse migration. Collaboration across different teams, including IT, data management, and business units, is often necessary to address these challenges effectively.


Data warehouse migration to the cloud: Why and how?

Data warehouse migration to the cloud involves transferring your existing on-premises or legacy data warehouse to a cloud-based solution. This strategic move is often driven by the need for greater scalability, performance, and cost-effectiveness that cloud platforms can offer.

Beyond mere data transfer, this migration also involves adapting schema, transforming data, and potentially re-architecting your entire data warehouse environment to fit into the cloud infrastructure. Below, we explore various aspects that are part and parcel of this transition.

Why migrate?


Before even embarking on the journey of cloud migration, it’s essential to understand the drivers behind such a move. Whether it’s the scalability that cloud offers, the promise of reduced operational costs, or access to advanced analytics capabilities, having a clear set of objectives can guide a successful migration process.

7 Significant steps in data warehouse migration to cloud


Migrating a data warehouse to the cloud is a multifaceted process that goes beyond just moving data from point A to point B. It involves strategic planning, technical expertise, and ongoing governance.

Here are the steps:

1. Data assessment and inventory

The first step in the migration process is to perform a comprehensive assessment of the existing data. This involves cataloging what types of data are stored, understanding their dependencies, and identifying which datasets are most critical to business operations.

2. Choosing the right cloud service

The choice of cloud service is critical and will depend on a variety of factors including cost, scalability, and specific feature sets tailored to your needs.

Providers like Amazon Redshift, Google BigQuery offer a range of options and it’s crucial to select one that aligns well with your objectives.

3. Schema migration and transformation

One of the technical challenges involves adapting the existing data warehouse schema for the cloud. This can entail changes to table structures, data types, and relationships.

Tools exist that can automate parts of this process, but manual intervention is often necessary for complex transformations.

4. Data transfer and loading

Transferring data to the cloud requires careful planning to minimize downtime and data loss. Bulk transfer methods, incremental updates, and parallel transfers are some of the techniques used to efficiently move data.

5. Testing and validation

Once the data is transferred, extensive testing is crucial to ensure data integrity, performance, and security. This phase helps verify that all components, from simple queries to complex analytical jobs, function as expected in the new environment.

6. Governance and security

Migrating to the cloud also involves a shift in how data is governed and secured. Compliance with data privacy laws, implementing encryption, and setting up role-based access controls are key considerations in this step.

7. Monitoring and optimization

After the migration is complete, continuous monitoring is vital to ensure that the system is performing optimally and securely. This involves setting up alerts for anomalies and performance metrics, and fine-tuning the system as needed.

When done right, the benefits can be transformative, offering unprecedented scalability, cost savings, and new avenues for data analytics.


7 Critical data warehouse migration utilities

The age of digital transformation demands agility, and organizations need to constantly upgrade and migrate their systems to stay relevant and efficient. Legacy systems, with their limitations and outdated architectures, often hinder progress.

Data warehouse involve the following utilities:

  1. Seamless data transfer
  2. Accuracy and integrity
  3. Speed and efficiency
  4. Scalability
  5. Cost savings
  6. Support and documentation
  7. Future-ready

Let’s understand each of them in details.

1. Seamless data transfer


  • Traditional migration often involves convoluted processes, multiple tools, and considerable human intervention.
  • With the ServiceNow accelerator, data can be transferred seamlessly from various legacy systems directly to the ServiceNow platform, reducing the complexity involved in such operations.
  • The need for efficient migration solutions is more pertinent than ever, given the rapid evolution of data storage technologies and increasing data volumes.

2. Accuracy and integrity


  • The utility ensures data accuracy and integrity. Gone are the days when manual data imports would lead to errors, missing data, or mismatched records.
  • The automated processes of this tool ensure that every bit of data finds its rightful place in the new system.
  • Modern utilities ensure that data, even from disparate sources, retains its structure and relationships. It guarantees that the migrated data reflects the original source with no alterations or unintended modifications.

3. Speed and efficiency


  • Data migration isn’t just about transferring data; it’s about doing it quickly.
  • The longer data migration takes, the longer systems might need to be offline, and the more disruptive it can be to operations.
  • The ServiceNow accelerator significantly reduces the migration timeline, ensuring minimal downtime.
  • Automated workflows within the utility can considerably reduce the migration timeframe. Instead of manual transfer processes, which are both tedious and prone to errors, the utility handles migrations swiftly.

4. Scalability


  • Whether you’re migrating a few gigabytes of data or several terabytes, the utility is built to handle migrations of any scale.
  • This scalability ensures that even as your organization grows, data migrations remain a breeze.
  • Whether a company is looking to migrate a few terabytes or several petabytes of data, a robust migration utility can handle it, scaling its operations accordingly.

5. Cost savings


  • With reduced human intervention and minimized errors, organizations can expect significant cost savings. Moreover, faster migrations mean reduced labor hours and quicker return to normal operations.
  • Faster migrations ensure that any downtime is kept to a minimum, thus reducing potential lost revenue or productivity.

6. Support and documentation


  • The ServiceNow accelerator isn’t just a tool—it comes with a wealth of documentation and support. This ensures that users, whether they’re new to ServiceNow or seasoned pros, have all the resources they need to conduct successful migrations.
  • Detailed documentation ensures users understand every aspect of the utility, from basic operations to troubleshooting.

7. Future-ready


  • The utility is designed not just for the needs of today but also for the demands of tomorrow. As ServiceNow continues to evolve, so does the accelerator, ensuring that it remains the most effective data migration tool for the platform.
  • A future-ready utility receives regular updates, ensuring it remains compatible with the latest data storage technologies and best practices.

In an era where data is paramount, having an efficient and reliable data migration tool is a necessity. The ServiceNow accelerator data migration utility meets this demand, offering organizations a streamlined, accurate, and fast way to transfer their data from legacy systems to the ServiceNow platform.

By choosing this utility, businesses are not just opting for a tool; they’re investing in a future where data migrations are hassle-free and efficient.


Top 4 data warehouse migration tools

With businesses constantly evolving, many find it necessary to migrate their data warehouses to more scalable, flexible, or cost-effective platforms. This can be due to various reasons: vendor changes, cloud adoption, better features, or reduced operational costs.

  1. Amazon web services (AWS) database migration service (DMS)
  2. Google cloud’s big query data transfer service
  3. Azure Data Factory
  4. Snowflake’s data sharing and snowpipe

Let’s learn in details about these.

1. Amazon web services (AWS) database migration service (DMS)


  • AWS DMS allows users to migrate databases to AWS easily and securely. It supports the migration of data to and from most widely used commercial and open-source databases. It migrates data between different types of database systems.
  • This feature supports data replication with high availability and consolidating databases into a petabyte-scale data warehouse.
  • Use change data capture (CDC) to ensure data is consistently replicated and migration can occur without significant operational impact.

2. Google cloud’s big query data transfer service


  • This service automates the movement of data into BigQuery from SaaS applications like Google Marketing Platform, YouTube, and partner SaaS applications like Teradata and AWS.
  • Schedule the data to import tasks on a daily, weekly, or monthly basis and import historical data with ease.
  • There is no need to manage any infrastructure or software.

3. Azure data factory


  • Azure data factory is a cloud-based data integration service that orchestrates and automates the movement and transformation of data.
  • It can move data between various supported data stores and perform transformations using compute services like Azure HDInsight and Azure Machine Learning.
  • Monitor all of your data pipelines at a glance using a visual interface and move data across on-premises and cloud environments.
  • Users don’t have to manage infrastructure, and it provides fault tolerance out of the box.

4. Snowflake’s data sharing and snowpipe


  • Snowflake offers features like Data Sharing and Snowpipe to migrate and continuously load data into its platform without any coding.
  • Zero-copy cloning allows for creating copies of data without duplicating storage or impacting performance.
  • Snowpipe automatically scales to handle the size of incoming data and it allows for near real-time ingestion of data as soon as it becomes available.

Choosing the right data warehouse migration tool depends on the specific requirements of the project, such as the source and target platforms, the volume of data, the complexity of transformations, and the desired downtime.

It’s advisable to conduct a detailed assessment of the data landscape and migration goals before deciding on a tool.


Bottom line

  • Data warehouse migration represents a critical step in modernizing and optimizing business intelligence operations. Successful migration demands meticulous planning, strategic thinking, and the right set of tools.
  • By adhering to best practices, organizations can navigate the challenges that come with this transformative endeavor. The migration types – from on-premises to cloud, cloud-to-cloud, legacy to modern, and hybrid – offer different approaches, each catering to distinct needs and considerations.
  • Key utility factors like seamless data transfer, accuracy, efficiency, scalability, cost savings, support, and future-readiness underscore the importance of choosing the right migration tool.
  • Top tools like AWS Database Migration Service, Google Cloud’s BigQuery Data Transfer Service, Azure Data Factory, and Snowflake’s offerings showcase the diversity of options available to streamline the migration process.
  • Ultimately, a successful data warehouse migration hinges on a well-structured project plan, precise tool selection, and a commitment to optimizing data operations for the future. As businesses continue to adapt to evolving technology landscapes, a strategic and well-executed migration can offer transformative gains and position organizations for enhanced data-driven success.


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