Teradata to Snowflake Migration: Complete Guide (With Steps)

Migrating from a traditional data warehouse like Teradata can seem complex.

However, there are several reasons that lead companies to make this change.

A cloud-native platform like Snowflake promises improved flexibility, scalability, and new ways to work with data. 

This guide explains what you need to know about migrating from Teradata to Snowflake.

Why Use Snowflake Over Teradata?

Snowflake is a data warehouse built for the cloud. It has several key benefits over older systems like Teradata. This makes it a popular choice for many businesses that want modern tools, speed, and advanced analytics.

Snowflake was built from the ground up for the cloud. Its system separates computing power from data storage. This setup makes it possible to scale resources up or down almost instantly and independently. 

This helps control costs. In contrast, Teradata's on-site hardware is often fixed and needs a lot of planning to expand.

Here are More Reasons People Choose Snowflake Over Teradata:

1. Performance and Multiple Users: Snowflake's unique design lets different groups and tasks run on their own separate computer clusters, called Virtual Warehouses. This means they don't fight for the same resources, even when using the same data. This greatly improves performance when many queries run at once. With Teradata, different tasks competing for resources can be a problem.
   
2. Flexible Data Support and Connections: Snowflake is built to handle both structured and semi-structured data (like JSON, Avro, XML, and Parquet). You don't need complex processes to load this data. It also has a growing number of connectors that work with popular business intelligence, data loading, and data science tools. These connections often work more smoothly than with older systems.
   
3. Secure Data Sharing and Teamwork: Snowflake's Secure Data Sharing feature makes it possible to share live, controlled data with other Snowflake accounts. This can be done with internal or external users without copying or migrating the data. This is a major new feature for teamwork, selling data, and department-to-department analytics. It is much simpler than old data sharing methods.
4. Cost-Effectiveness and Pricing Model: Snowflake’s pay-as-you-go model means you only pay for the storage and computing power you use. This often leads to better cost efficiency, especially for changing workloads. Teradata usually involves a large upfront payment for hardware and software, plus ongoing upkeep costs. While moving to the cloud requires careful cost management, Snowflake's model gives greater detail and control.
5. Simpler Management and Upkeep: As a fully managed service, Snowflake handles most administrative work like software updates and system management. This lightens the workload for IT teams when compared to managing on-premise Teradata systems. Teradata requires dedicated database administrators for tuning, upkeep, and upgrades.
6. Ecosystem and New Features: As a modern cloud platform, Snowflake gets fast new updates and has a growing community. It regularly releases new features and improvements, keeping up with the changing world of data.

5 Steps to Migrate from Teradata to Snowflake

To successfully move from Teradata to Snowflake, you need careful planning and precise execution. A structured method will keep disruptions to a minimum. It also helps confirm data correctness and performance in the new system. Here are the main steps:

1. Review Your Existing Teradata System and Define the Project Scope

A full review of your current Teradata setup is very important for a structured migration plan.

• List Your Data Assets: Identify all active databases, schemas, tables, views, and users. Document Teradata-specific items like macros, stored procedures, UDFs (User Defined Functions), and BTEQ scripts. Note any custom data types and indexing methods.
  
• Examine Workloads and Connections: Profile your Teradata workloads to understand query patterns and resource use. Find connections between data objects, data jobs, and the reports or tools that use them. Understanding these relationships is essential for choosing what to move first and keeping business running.
  
• Define the Project's Scope and Goals: Clearly state what you want to achieve. Are you migrating all Teradata databases, or just starting with a smaller test project? Which Teradata features need to be copied? Which ones can be updated using Snowflake's newer capabilities? Set clear success targets for performance, cost, and features.
  
• Understand Data Structures and Code: Know that Teradata and Snowflake have different SQL styles and data types. Plan how Teradata's data definitions and commands will be translated to Snowflake. Think about how Teradata-specific SQL and scripts will be updated or rewritten. This often needs special tools or knowledge.

2. Plan the Teradata Migration and the Snowflake Setup

With a clear picture of your current state, you can plan the technical parts of the move.

I. Choose Your Snowflake Edition and Cloud Company: Decide on the right Snowflake edition (Standard, Enterprise, Business Critical) based on your needs for features and security. Select the cloud company (AWS, Azure, GCP) and location that best fits your data storage and speed requirements.‍

II. Select Data Migration and Loading Tools: Look at different tools and methods for getting data from Teradata and loading it into Snowflake. Your choices include:

1. Built-in Utilities: Using Teradata tools for export and Snowflake tools for import (like the COPY INTO command or Snowpipe for ongoing data flows).
   
2. Third-Party Data Tools: Using existing or new data loading tools that work with both Teradata and Snowflake (like Informatica, Talend, or dbt). This may mean re-working existing jobs.
   
3. Specialized Migration Platforms: Using tools made just for data warehouse moves that can automate schema changes, data checks, and code updates.
   

III. Develop a Schema and Code Change Plan: Create a detailed map for data types between Teradata and Snowflake. Plan the approach for changing Teradata SQL, stored procedures, macros, and scripts. This might involve automated tools followed by manual checks and testing.‍

IV. Design the Snowflake Structure: Plan your Snowflake account layout, including databases, schemas, and roles. Design your virtual warehouse settings (like size and auto-off) for the different workloads you found during your review. Plan your data loading method and how you'll use cloud storage.

V. Set a Timeline and Goals: Develop a realistic project plan. It should have clear stages, goals, who is responsible for what, and plans for what to do if something goes wrong.

3. Prepare the Snowflake System and Do a Test Move

Before the full move, prepare Snowflake and test the process completely.

• Configure Snowflake: Set up your Snowflake account, virtual warehouses, databases, schemas, users, and roles as you designed them. Set up network rules, security connections, and resource monitors.
  
• Data Cleanup and Tuning (Optional): You can choose to clean or archive old data in Teradata before migrating it. This can make the move smaller and improve data quality in Snowflake. It is also a chance to adjust data models for Snowflake.
  
• Test Move: Select a typical sample of your data for a test move. This helps find possible problems with data extraction, loading, schema changes, and code updates. It also confirms that your chosen tools and processes work.
  
• User Testing for the Test Move: Have key business users and data analysts test the moved data and updated reports in Snowflake. They should check data correctness, query performance, and features against the original Teradata system. Get feedback and make any needed changes to the migration plan.

4. Carry Out the Full Move and Check the Data

After a successful test and updated plan, you can begin the Teradata to Snowflake migration.

• Schedule Downtime (if needed): Depending on your approach, you might need downtime or a period of limited access to some Teradata applications. Tell everyone involved about this well ahead of time.
  
• Perform the Full Data Move: Carry out the move as planned, using your chosen tools. This involves getting historical data from Teradata, changing it if needed, and loading it into Snowflake. Watch the process closely for any errors.
  
• Move Code and Applications: Move and update all data definitions, commands, stored procedures, data jobs, and reports so they work with Snowflake.
  
• Complete Data Check: After the move, do thorough checks by comparing data in Snowflake against Teradata. Confirm the correctness and completeness of all moved items. Use row counts and specific queries. Check that the data rules in updated reports are still correct.
  
• Test Snowflake Features and Performance: Confirm that all Snowflake settings, virtual warehouses, and security rules are working correctly. Run performance tests on important queries to make sure they meet your standards. Adjust queries and warehouse settings as needed.
  

5. After the Move: Next Steps, Training, and Support

The move is not finished after the data is transferred. Several steps afterward are very important for long-term success.

• User Training: Give good training to all users (analysts, data scientists, developers) on Snowflake's system, its SQL style, and best practices for writing queries and managing costs.
  
• Update Documents and Processes: Update all process documents, data dictionaries, and system diagrams to show the new Snowflake-based setup and any changed workflows.
  
• Monitor and Improve: Constantly watch Snowflake's performance and credit use. Get regular user feedback. Find areas for more improvement in queries, warehouse settings, or data processes. Put cost controls and alerts in place.
  
• Turn Off Teradata: Once you are sure that Snowflake is stable, working fully, and all data and applications have been moved and checked, plan to turn off the Teradata system. Make sure all data is backed up according to your company's rules.
  
• Ongoing Support and Governance: Set up a support system for users to ask questions. Put data governance rules in place for the new Snowflake system.

What are the Challenges When Migrating From Teradata to Snowflake?

Moving from Teradata to Snowflake is a good step but has its own set of difficulties. Understanding these can help you plan and prepare.

1. SQL Style Differences and Code Changes: Teradata SQL has special functions and procedural languages that do not work directly in Snowflake SQL. Changing complex macros, stored procedures, and code in applications can take a lot of time, may have errors, and often needs special tools and manual work.
   
2. Performance Tuning and Adjustments: Teradata and Snowflake have very different designs. The methods that make Teradata perform well (like choosing a Primary Index) do not apply to Snowflake. Snowflake's performance depends on micro-partitions, clustering keys, and the size of virtual warehouses. Adjusting queries and workloads for Snowflake can be a new skill to learn.
   
3. Data Type Matching: While many standard data types are similar, there can be differences in how they work. Some Teradata-specific data types need careful mapping and testing in Snowflake to avoid losing data.
   
4. Reworking Data Loading Tools: Existing data jobs made for Teradata often need big changes or to be completely rewritten to work well with Snowflake. This includes changing connectors and adjusting data logic for Snowflake's design.
   
5. Large Data Volumes: Moving huge amounts of historical data from Teradata to Snowflake can be a long process. It is limited by network speed and how fast data can be extracted and loaded. Planning for the least amount of downtime during the switch is very important.
   
6. User Skill Gaps and Training: Teams used to Teradata's tools and methods will need training and time to get used to Snowflake's system and cloud-first management. It is important to address any skill gaps for a successful change.
   
7. Security Model Changes: Changing Teradata's security model (with its users, roles, and permissions) to Snowflake's system requires careful planning. You need to get equal or better security and meet all regulations in the cloud.
   
8. Cost Management with a New Model: While Snowflake's pay-as-you-go model is flexible, it needs close watching to control costs. Queries that are not well-written or warehouses that are the wrong size can lead to surprise bills. This is a change from Teradata's more predictable, but often higher, fixed costs.

What are the Best Practices When Migrating From Teradata to Snowflake?

Following best practices can greatly lessen risks and lead to a smoother switch from Teradata to Snowflake.

Thorough Planning and Review

Before you start, do a full review of your Teradata system. This includes schemas, data amounts, connections, and data jobs.

Clearly define the project's scope, goals, and measures of success. Develop a detailed moving plan with schedules, people, and ways to handle risks.

Use Automation for Schema and Code Changes

Use automated tools to change Teradata data definitions (schemas, tables) and SQL code (macros, queries) to Snowflake-friendly formats.

While these tools might not convert everything perfectly, they greatly cut down on manual work. Plan to have people review and fix the converted code.

Use a Phased or Step-by-Step Approach

Avoid trying to move everything at once, especially for big and complex systems. Instead, move in stages, perhaps by topic or department.

Start with a test project to check your tools and processes. This will give you early successes and lessons.

Prioritize Data Checking and Testing

Put strong data checks in place at each stage of the move. This is to confirm data correctness and completeness.

Run thorough performance tests of important queries in Snowflake. Compare the results against how they ran in Teradata.

Redesign and Adjust for Snowflake

Don't just copy everything as-is. Use this as a chance to redesign data models and data processes. This will help you use Snowflake's unique features, like its ability to handle semi-structured data, use clustering keys, and separate computing from storage. Adjust queries so they run well on Snowflake's engine.

Proper User Training and Change Management

Invest in good training for all user groups on Snowflake's features, SQL style, and best practices for query writing and cost control. Have a plan to manage the change, listen to user worries, and help people adopt the new platform.

Engage Experts or Use Specialized Tools

For complex moves, think about working with consultants who have deep knowledge of both Teradata and Snowflake. You can also use special third-party moving platforms. Their experience can help you with difficult challenges, speed up the move, and lower risks.

Build Security and Governance from Day One

Set up a strong security model in Snowflake, mapping roles and permissions carefully from Teradata. Set up network rules, encryption, and access controls.

Establish data governance practices for the cloud, dealing with data quality, history, and rule-following.

Plan for Ongoing Improvements and Cost Management

Set up continuous monitoring of Snowflake's performance and credit use.

Regularly review query performance, warehouse usage, and storage costs. Put improvement methods and cost controls in place to get long-term value from your Snowflake setup.

Get Help When Migrating From Teradata to Snowflake With Entrans

Experienced professionals from Entrans can help with the review, planning, schema and code changes, data moving, and performance tuning. They can also assist with user training, helping you use the full power of Snowflake well.

A team of data engineers and experts brings a lot of experience from many migration projects. This helps you avoid common problems and reach your business goals faster.

Want to know more about how expert services can simplify your cloud data warehouse move? Book a free 30-minute consultation call!