1. Identify the source of the PostgreSQL 42939 error:

SELECT * FROM pg_stat_activity WHERE state = 'idle in transaction'

2. Check the application code for any open transactions that are not being closed properly:

BEGIN;SELECT * FROM table_name;COMMIT

3. If the application code is not the source of the issue, check the PostgreSQL configuration settings:

SHOW max_connections;

4. Increase the max_connections setting if necessary:

ALTER SYSTEM SET max_connections = '100'

5. Restart the PostgreSQL server: [.code]sudo service postgresql restart[.code]

sudo service postgresql restart

6. Monitor the PostgreSQL server for any further occurrences of the PostgreSQL 42939 error:

SELECT * FROM table WHERE id = 1;should be changed toSELECT * FROM table WHERE id = 1)

7. Use an automated database observability tool to monitor and fix the PostgreSQL 42939 in question. Automated database observability tools can provide real-time insights into the performance and health of your database, allowing you to quickly identify and address any issues that may arise. Additionally, these tools can provide alerts when certain thresholds are exceeded, allowing you to take proactive steps to prevent any further issues.