Monitoring query logs

If you want to profile what your server has done, one of the most effective ways is to analyze the logs of what queries it executed. There are many ways you can approach that problem, and several tools available to then analyze the resulting log files.

Basic PostgreSQL log setup

This is what the default settings in the postgresql.conf setting look like for the main logging setup parameters:

log_destination = 'stderr' 
logging_collector = off 
log_line_prefix = '' 
log_directory = 'pg_log' 
log_filename = 'postgresql-%Y-%m-%d_%H%M%S.log' 

It's important to know what all these lines mean before changing them:

• log_destination: Write server log messages to the standard error output of the process starting the server. If you started the server manually, these might appear right on your console. If you sent the server output to another spot, either using the pg_ctl -l option or by using command-line redirection, they'll go to the file you specified there instead.
• logging_collector...