1. Check the PostgreSQL log files for any errors or warnings that may indicate the cause of the issue.

tail -f /var/log/postgresql/postgresql-9.6-main.log

2. Check the PostgreSQL configuration files for any misconfigurations that may be causing the issue.

cat /etc/postgresql/9.6/main/postgresql.conf

3. Check the PostgreSQL system tables for any inconsistencies that may be causing the issue.

SELECT * FROM pg_stat_activity;

4. Check the PostgreSQL system processes for any issues that may be causing the issue.

ps aux | grep postgres

5. Check the PostgreSQL system memory for any issues that may be causing the issue.

free -m

6. Check the PostgreSQL system disk for any issues that may be causing the issue.

df -h

7. If the issue persists, consider using an automated database observability tool to monitor and fix the PostgreSQL 22020 in question. Automated database observability tools can provide real-time insights into the performance and health of the database, allowing for quick and easy diagnosis and resolution of issues.