Causes the duration of every completed statement to be logged. The default is
off. Only superusers and users with the appropriate
SET privilege can change this setting.
For clients using extended query protocol, durations of the Parse, Bind, and Execute steps are logged independently.
The difference between enabling
log_duration and setting log_min_duration_statement to zero is that exceeding log_min_duration_statement forces the text of the query to be logged, but this option doesn't. Thus, if
on and log_min_duration_statement has a positive value, all durations are logged but the query text is included only for statements exceeding the threshold. This behavior can be useful for gathering statistics in high-load installations.