BufferedEvents Compound Primary Key #568
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What Changed?
Move the auto-increment Id for BufferedEvents below the primary key to make this a bit more explicit of the true ordering necessary. This is not necessary for Vitess but should make any future alterations here easier by physically clustering records together that are part of the same runId. Additionally, the true solution is to use the nextEventId in the database, but this is not currently guaranteed to be unique, so nesting the auto-incrementing Id should make a key change to an application specified id simpler in the future.
Re: Vitess - This should not require a Vitess sequences table as the VIndex that should be used by Vitess here (shard_id) will does not use the AutoIncrement table and we are okay with local ordering for each MySQL instance.
Risks?
No major risks as application code changes are not required as the application currently uses
(shard_id, namespace_id, workflow_id, run_id)as the lookup key. This should see some read performance increases by reducing fragmentation on the read path. Write performance could theoretically suffer slightly in a non-sharded MySQL setup. Will watch our stress tests for any changes.