-- Admin read-model foundation (#140). The Series list's default order is
-- least-recently-checked first, so the table — which has only its primary key
-- today — gets an index that can serve it. A grouped query over a join may
-- ignore the index, so this is a judgement, not a measurement: re-time on real
-- data before adding a second.
CREATE INDEX series_latest_checked_at_idx ON series (latest_checked_at);

-- force_poll_at is the "ask for one Series to be checked now" stamp (#146).
-- Zero means never forced; nothing reads the column before that ticket wires
-- it, so it lands here unused.
ALTER TABLE series ADD COLUMN force_poll_at bigint NOT NULL DEFAULT 0;