Creates and drops the Aurora Meter core tables, in versions.

A host migration delegates here, so schema changes ship as new versions of this module rather than as edits to the host's migration file. Every version is idempotent (create_if_not_exists), so up/1 can safely run from version 1 each time.

Fresh install (generated by mix aurora_meter.gen.migration):

def up, do: AuroraMeter.Migration.up()
def down, do: AuroraMeter.Migration.down()

Upgrading an existing install to a newer schema version, add a migration that runs only the new versions:

def up, do: AuroraMeter.Migration.up(from: 3)
def down, do: AuroraMeter.Migration.down(to: 3)

Versions

• 1 — aurora_meter_subscriptions, aurora_meter_counters, aurora_meter_events
• 2 — aurora_meter_history (UTC day buckets for AuroraMeter.history/3)
• 3 — aurora_meter_credit_balances, aurora_meter_credit_transactions (the prepaid ledger behind AuroraMeter.Credits)
• 4 — promotional_after on aurora_meter_credit_transactions, so the promotional figure can be rebuilt from the log like balance and held
• 5 — a partial index on open holds, so the sweep for reservations nothing will ever close does not scan the whole ledger
• 6 — aurora_meter_flush_receipts, committed atomically with counter and history deltas to deduplicate retries after uncertain writes