docs: Add automatic maintenance (cron) scheduling instructions and examples

README.md

@@ -55,7 +55,25 @@ This procedure should be scheduled to run periodically (e.g., daily via `pg_cron
 ```sql
 CALL partitions.run_maintenance();
 ```
+### Automatic Maintenance (Cron)
 
+To ensure partitions are created in advance and old data is cleaned up, the maintenance procedure should be scheduled to run automatically. 
+
+It is recommended to run the maintenance **twice a day** (e.g., at 05:30 and 23:30).
+*   **Primary Run**: Creates new future partitions and drops old ones.
+*   **Secondary Run**: Acts as a safety check. Since the procedure is idempotent (safe to run multiple times), a second run ensures everything is consistent if the first run failed or was interrupted.
+
+**Example Crontab Entry (`crontab -e`):**
+```bash
+# Run Zabbix partition maintenance twice daily (5:30 AM and 5:30 PM)
+30 5,23 * * * psql -U zabbix -d zabbix -c "CALL partitions.run_maintenance();" >> /var/log/zabbix_maintenance.log 2>&1
+```
+
+**Docker Environment:**
+If running in Docker, you can execute it via the container:
+```bash
+30 5,23 * * * docker exec zabbix-db-test psql -U zabbix -d zabbix -c "CALL partitions.run_maintenance();"
+```
 ## Monitoring & Permissions
 
 System state can be monitored via the `partitions.monitoring` view. It includes a `future_partitions` column which counts how many partitions exist *after* the current period. This is useful for alerting (e.g., trigger if `future_partitions < 2`).