feat: Initial commit for 8.0 branch. history_json was added.

postgresql/procedures/README.md

@@ -61,7 +61,7 @@ This procedure should be scheduled to run periodically (e.g., daily via `pg_cron
 ```sql
 CALL partitions.run_maintenance();
 ```
-### Automatic Maintenance (Cron)
+### Automatic Maintenance
 
 To ensure partitions are created in advance and old data is cleaned up, the maintenance procedure should be scheduled to run automatically. 
 
@@ -69,16 +69,70 @@ It is recommended to run the maintenance **twice a day** (e.g., at 05:30 and 23:
 *   **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.
 
+There are three ways to schedule this, depending on your environment:
+
+#### Option 1: `pg_cron` (If you use RDS/Aurora)
+If you are running on managed PostgreSQL (like AWS Aurora) or prefer to keep scheduling inside the database, `pg_cron` is the way to go.
+
+1. Ensure `pg_cron` is installed and loaded in `postgresql.conf` (`shared_preload_libraries = 'pg_cron'`).
+2. Run the following to schedule the maintenance:
+```sql
+CREATE EXTENSION IF NOT EXISTS pg_cron;
+SELECT cron.schedule('zabbix_maintenance', '30 5,23 * * *', 'CALL partitions.run_maintenance();');
+```
+*Where:*
+*   `'zabbix_maintenance'` - The name of the job (must be unique).
+*   `'30 5,23 * * *'` - The standard cron schedule (runs at 05:30 and 23:30 daily).
+*   `'CALL partitions.run_maintenance();'` - The SQL command to execute.
+
+
+#### Option 2: `systemd` Timers
+For standard Linux VM deployments, `systemd` timers are modern, prevent overlapping runs, and provide excellent logging.
+
+1. Create a service file (`/etc/systemd/system/zabbix-partitioning.service`):
+```ini
+[Unit]
+Description=Zabbix PostgreSQL Partition Maintenance
+
+[Service]
+Type=oneshot
+User=zabbix
+# Ensure .pgpass is configured for the zabbix user so it doesn't prompt for a password
+ExecStart=/usr/bin/psql -U zabbix -d zabbix -c "CALL partitions.run_maintenance();"
+```
+
+2. Create a timer file (`/etc/systemd/system/zabbix-partitioning.timer`):
+```ini
+[Unit]
+Description=Zabbix Partitioning twice a day
+
+[Timer]
+OnCalendar=*-*-* 05,23:30:00
+Persistent=true
+
+[Install]
+WantedBy=timers.target
+```
+
+3. Enable and start the timer:
+```bash
+systemctl daemon-reload
+systemctl enable --now zabbix-partitioning.timer
+```
+
+#### Option 3: Standard Cron
+This is the legacy, simple method for standard VMs and containerized environments.
+
 **Example Crontab Entry (`crontab -e`):**
 ```bash
-# Run Zabbix partition maintenance twice daily (5:30 AM and 5:30 PM)
+# Run Zabbix partition maintenance twice daily (5:30 AM and 11:30 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:
+If running in Docker, you can execute it via the container's host:
 ```bash
-30 5,23 * * * docker exec zabbix-db-test psql -U zabbix -d zabbix -c "CALL partitions.run_maintenance();"
+30 5,23 * * * docker exec zabbix-db psql -U zabbix -d zabbix -c "CALL partitions.run_maintenance();"
 ```
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