-- Ledger fixes.
-- * Mutating tools that need no Computer (memory, schedules) are journaled
--   too, so computer_id must be nullable.
-- * The outbox is polled every 200 ms; give the undelivered scan an index and
--   let retention drop delivered rows.
-- * `computer_operations.id` is now `{bot_id}:{operation_id}`; the extra
--   (id, payload_hash) unique index never added anything over the PK.

ALTER TABLE computer_operations ALTER COLUMN computer_id DROP NOT NULL;

DROP INDEX IF EXISTS computer_operations_id_hash;

CREATE INDEX IF NOT EXISTS operation_outbox_pending_idx
    ON operation_outbox (created_at) WHERE NOT delivered;

CREATE INDEX IF NOT EXISTS computer_operations_bot_idx
    ON computer_operations (bot_id, created_at);