- Add materialized views for list -> subscriber counts, dashboard chart,
and dashboard aggregate stats that slow down significantly on large
databases (with millions or tens of millions of subscribers). These
slow queries involve full table scan COUNTS().
- Add a toggle to enable caching slow results in Settings -> Performance.
- Add support for setting a cron string that crons and periodically
refreshes aggregated stats in materialized views.
Closes#1019.
- On boot, the app now checks if the DB version matches its
expected version and refuses to start if there are pending
migrations to be run.
- The new `--upgrade` flag runs data migrations from the last
recorded migration (in the settings table) to the latest one
in the binary.
- Migrations are DB/arbitrary logic functions in .go files in
internal/migrations.
- All migration functions are idempotent.
