How to migrate Legacy Data onto ARAS system

 1. Data Preparation

  • Understand Legacy Database:
    • Document Structure: Carefully document the schema of your legacy database tables (column names, data types, relationships, primary/foreign keys).
    • Data Inspection:
      • Examine the data within each table.
      • Identify and document any potential data quality issues (e.g., missing values, invalid data, inconsistencies).
      • Check for data type compatibility between the legacy database and the new database.
    • Data Sampling: Extract a small sample of data from each table for testing and validation purposes.


2. Data Migration Order

  • 1. AccountTypes: Migrate data from the legacy AccountTypes table to the new AccountTypes table. This is crucial as other tables rely on the account_type_id foreign key.
  • 2. Customers: Migrate data from the legacy Customers table to the new Customers table.
  • 3. Vendors: Migrate data from the legacy Vendors table to the new Vendors table.
  • 4. Accounts: Migrate data from the legacy Accounts table to the new Accounts table. Ensure that the account_type_id and parent_id foreign keys in the new Accounts table correctly reference the corresponding records in AccountTypes and Accounts tables.
  • 5. CompanySettings: Migrate data from the legacy CompanySettings table to the new CompanySettings table.
  • 6. Transactions: Migrate data from the legacy Transactions table to the new Transactions table. Crucially, ensure the customer_id, vendor_id, and account_id in each transaction record correctly reference the corresponding IDs in the Customers, Vendors, and Accounts tables.
  • 7. TransactionItems: Migrate data from the legacy TransactionItems table to the new TransactionItems table. Ensure the transaction_id foreign key correctly references the id in the Transactions table.
  • 8. Ledgers: Migrate data from the legacy Ledgers table to the new Ledgers table. Ensure the transaction_id and account_id foreign keys correctly reference the id in the Transactions and Accounts tables, respectively.
  • 9. Users: Migrate data from the legacy Users table to the new Users table.
  • 10. UserRoles: Migrate data from the legacy UserRoles table to the new UserRoles table.
  • 11. Permissions: Migrate data from the legacy Permissions table to the new Permissions table.
  • 12. RolePermissions: Migrate data from the legacy RolePermissions table to the new RolePermissions table. Ensure the role_id and permission_id foreign keys correctly reference the id in the UserRoles and Permissions tables, respectively.
  • 13. UserRoleAssignments: Migrate data from the legacy UserRoleAssignments table to the new UserRoleAssignments table. Ensure the user_id and role_id foreign keys correctly reference the id in the Users and UserRoles tables, respectively.

3. Data Transformation (If Necessary)

  • Data Cleaning:
    • Handle missing values (e.g., replace with NULL, impute values).
    • Correct data inconsistencies (e.g., invalid dates, incorrect data types).
    • Remove duplicate records.
  • Data Conversion:
    • Convert data types as needed to match the target database schema (e.g., convert date formats, adjust decimal precision).
    • Handle any specific data transformations required (e.g., currency conversions, data encoding).

4. Data Loading

  • Import Data into New Database:

    • Use appropriate tools (e.g., database client, scripting languages, bulk loading utilities) to import the cleaned and transformed data into the corresponding tables in the new database.
    • Follow the order of table migrations as outlined above to ensure data integrity and avoid foreign key constraint violations.

  • Data Validation:

    • Verify data integrity (e.g., check for missing values, duplicate records, referential integrity constraints).
    • Compare key data points (e.g., counts, sums, averages) between the legacy and new databases to ensure data consistency.

5. Testing and Verification

  • Test Business Processes:
    • Test key business processes that rely on the migrated data to ensure they function correctly in the new environment.
  • Performance Testing:
    • Conduct performance tests to evaluate the query performance and overall system performance with the migrated data.
  • Address Issues:
    • Identify and resolve any issues or discrepancies discovered during testing.

6. Post-Migration Activities

  • Data Monitoring:
    • Establish ongoing monitoring of data quality and integrity in the new database.
  • Data Maintenance:
    • Implement a data maintenance plan to ensure data accuracy and consistency over time.
  • Documentation:
    • Document the entire migration process, including steps, challenges encountered, and solutions implemented.

Tools:

  • Database Clients: MySQL Workbench, pgAdmin, DBeaver
  • Scripting Languages: Python, SQL, Perl, Bash
  • ETL Tools: Informatica PowerCenter, Talend, Apache NiFi

Important Notes:

  • Prioritize Data Security: Implement strong security measures throughout the migration process to protect sensitive data.
  • Develop a Rollback Plan: Have a well-defined rollback plan in place in case of any unforeseen issues or data corruption.
  • Testing is Crucial: Thorough testing is essential to ensure data accuracy and system stability after the migration.
  • Consult with Experts: If you encounter significant challenges, consider consulting with database professionals or data migration specialists for assistance.

This updated procedure emphasizes the importance of maintaining the correct order of table migrations to avoid foreign key constraints and ensure data integrity.