Added example: Show top 20 rooms by new events count in last

SQL-for-analyzing-Synapse-PostgreSQL-database-stats.md

@@ -64,6 +64,13 @@ device_lists_stream - 326903
 user_directory_search - 316433
 ```
 
+## Show top 20 rooms by new events count in last 1 day:
+```
+SELECT e.room_id, r.name, COUNT(e.event_id) cnt FROM events e
+LEFT JOIN room_stats_state r USING (room_id)
+WHERE e.origin_server_ts >= DATE_PART('epoch', NOW() - INTERVAL '1 day') * 1000 GROUP BY e.room_id, r.name ORDER BY cnt DESC LIMIT 20;
+```
+
 ## Show top 20 users on homeserver by sent events (messages) at last month:
 ```
 SELECT user_id, SUM(total_events)