Comparison of test_decoding and pglogical plugins in Amazon Aurora PostgreSQL for data migration using AWS DMS

This AWS Database Blog article compares two PostgreSQL logical decoding plugins, `test_decoding` and `pglogical`, for data migration using AWS Database Migration Service (DMS). The article provides a comprehensive analysis of their performance, advantages, and use cases in different migration scenarios.

• The study focused on tracking disk spills during logical replication and comparing plugin performance
• Test scenarios examined load impacts on both non-CDC and CDC tables using different plugins
• Key performance metrics were tracked using Amazon CloudWatch metrics

Key findings for each plugin:

• `pglogical` advantages:
  • Filters non-CDC tables at replication slot
  • Reduces network throughput requirements
  • Better for workloads with selective table replication
• `test_decoding` advantages:
  • Suitable when all tables need CDC replication
  • Preferred when capturing entire row data is critical
  • Works better with tables lacking primary key constraints

The authors recommend choosing the appropriate plugin based on specific migration requirements and following AWS migration best practices.