1. Identify the root cause of the PostgreSQL 2200B error:

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

2. Terminate any idle transactions that are causing the error:

SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE state = 'idle in transaction';

3. Increase the number of connections allowed in PostgreSQL:

ALTER SYSTEM SET max_connections = '1000';

4. Increase the amount of shared memory available to PostgreSQL:

ALTER SYSTEM SET shared_buffers = '1GB';

5. Increase the amount of memory available to PostgreSQL:

ALTER SYSTEM SET effective_cache_size = '2GB';

6. Increase the amount of disk space available to PostgreSQL:

ALTER SYSTEM SET temp_buffers = '128MB';

7. Monitor the performance of PostgreSQL using an automated database observability tool:An automated database observability tool can help monitor and fix PostgreSQL 2200B errors by providing real-time insights into the performance of the database. It can detect and alert on any potential issues, such as slow queries, long-running transactions, and memory or disk space issues. This can help identify the root cause of the error and provide recommendations for how to fix it.