PostgreSQL 12 High Availability Cookbook - Third Edition

How to do it...

Follow these steps to examine the PostgreSQL processes in various ways:

1. In our PostgreSQL connection, execute the following query to find the PID of the server backend assigned to us:

SELECT pg_backend_pid() AS pid; 

2. As our root-capable user, attach strace to the preceding PID (4200, for example) with this command:

sudo strace -p 4200

3. In our PostgreSQL connection, execute the following query to generate some activity:

SELECT 1;

4. In the Terminal where strace is running, press Ctrl + C to disconnect.
5. Attach strace again, but collect the statistics with the following command:

sudo strace -c -S calls -p 4200

6. Now, execute the following query to generate some complex activity:

SELECT * FROM information_schema.columns;