julien-duponchelle / python-mysql-replication

Pure Python Implementation of MySQL replication protocol build on top of PyMYSQL
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Parse ALTER TABLE ADD/DROP COLUMN statement and sync `table_map` #511

Open dongwook-chan opened 1 year ago

dongwook-chan commented 1 year ago

I've noticed that a recent change in the repository removed the ability to select from information_schema to retrieve column_schema. Instead, it was chosen to parse the optional metadata present in the table map event to obtain this schema. I understand the rationale behind this, but there's a caveat: if binlog_row_metadata is set to FULL, the optional metadata isn't always fully available. This can lead to incomplete or incorrect column schemas.

To address this gap, I've developed a feature that parses the DDL from the query event and updates the table_map accordingly. This ensures that even when binlog_row_metadata is set to FULL, we can accurately and consistently retrieve the column schema.

Changes Made:

Implemented DDL parsing from query events. Updated table_map to reflect changes from parsed DDL. Added necessary unit tests to ensure correctness and stability of the new feature. Benefits:

Ensures that column schemas are always accurate, even when binlog_row_metadata is set to FULL. Reduces reliance on optional metadata which might be incomplete. I'd appreciate it if you could review the changes and provide feedback. I believe this enhancement can add robustness to the way column schemas are determined, ensuring accuracy and consistency for all configurations.

sean-k1 commented 1 year ago

@dongwook-chan Could you change this pr to draft?

dongwook-chan commented 1 year ago

Sure! 😁😁