Pattern 1: Migration Using Code Modification

This migration process is designed for critical online environments, allowing secure roll-back. The application performs the synchronization between both databases.

Step 1: Migrate model
  1. Using an export or backup of the current DB and LX-LD

Step 2: Migrate application
  1. Migrate application: 99% of the SQL is compatible. For incompatibilities:
    • Alternative SQL will be proposed.
    • LeanXcale will be extended to support the functions used.

  2. Migrate Stored Procedure (e.g., PL/SQL): The procedures are proprietary to the current DB (e.g. Oracle PL/SQL). It will translate to an equivalent java process.
  3. Double writing: Modify the application to write to both databases.

Step 3: Data migration
  1. Append-only: Append-only or data with an updating timestamp is migrated. They can be read from backups to avoid overload problems in the production database or using an ETL. LX-LD or ETL (e.g. AWS Glue, Datafactory or Airbyte)
  2. Last Day: Last synchronization of the last period (typically the last day) and data without an updating timestamp. It can be performed during an idle window. LX-LD or ETL (e.g. AWS Glue, Datafactory or Airbyte)

Step 4: Parallel
  1. Original Database as Reading Master: Operate in parallel with the original database, using LeanXcale as the master.
  2. LeanXcale as Master Reader: Parallel with LeanXcale as Reading Master
  3. Original Database deactivation: LeanXcale remains as the only engine

Step 5: Optimization
  1. Application optimization to take advantage of LeanXcale capabilities (parallelization/multithreading).