What is empty statement record in PostgreSQL log?

Question

I changed PostgreSQL cluster configuration to log ALL statements and its duration, and it work correct, but periodically I see records like this:

2020-12-08 09:31:42.175 +05 [19041:app_name] LOG:  00000: duration: 0.046 ms
2020-12-08 09:31:42.175 +05 [19041:app_name] LOCATION:  exec_execute_message, postgres.c:2086

What could it be? log_line_prefix = '%m [%p:%a] '

Also, it's standby node and replicates primary.

Answer 1

You are seeing output from log_duration. That just emits the duration without the statement and is somewhat useless.

Set log_duration = off, log_statement = 'none' and log_min_duration_statement = 0, and you will get all statements logged along with their duration, which is usually the most useful setting.