pg_log_statements is a PostgreSQL extension that allows to log SQL statements for specific server processes: instead of setting log_statement parameter at instance level or database level, log_statement can be set for specific server processes.
pg_log_statements can be used in 2 different ways:
Either by using the server process identifier (pid): pid mode
Or by using a filter to enable logging from server process start to server process end (the filter clause specifies which server processed are going to enable log_statement=all): filter mode
