Denormalize event type for request and event logs

[ezekg]

Part 1 of 4. Improves performance for Dashboard metrics.

Prerequisites

• Cut new Keygen CE/EE versions so we release multi-user licenses before this.

Post deploy

Part 2 (in order of operations)

• Backfill denormalized event_type_event from event_types to event_logs.
• Add NOT NULL constraint to event_logs.event_type_event.
• Add index on event_logs.event_type_event.
• Run VACUUM ANALYZE event_logs.

Part 3 (in order of operations)

• Backfill denormalized event_type_id and event_type_event from event_logs to request_logs.
• Add NOT NULL constraints to request_logs.event_type_id and request_logs.event_type_event.
• Add indexes on request_logs.event_type_id and request_logs.event_type_event.
• Run VACUUM ANALYZE request_logs.

Part 4

• Update EventLog.for_event_type to use denormalized event_type_event column for strings.
• Update RequestLog.for_event_type to use denormalized event_type_event column.

[ezekg]

Should we be denormalizing event_type_id from event_log too? Would solve for the race condition touched on here.

[ezekg]

Possible race condition here since there's no guarantee an event log will be inserted after a request log. Need to rethink this (and write appropriate tests).

[ezekg]

Where is this being set?

[ezekg]

Closing because this is outdated and denormalizing a string column onto every event log row is going to be super expensive, storage-wise. I'd rather look into using materialized views or something to improve performance here.