BUG #6081: trigger CRUD log entries, or documentation not clear that triggers do not log

The following bug has been logged online:

Bug reference:      6081
Logged by:          Tom Hodder
Email address:      tom@limepepper.co.uk
PostgreSQL version: 8.4
Operating system:   Fedora 14 x86_64
Description:        trigger CRUD log entries, or documentation not clear
that triggers do not log
Details:

with this log directive set;
log_statement = 'mod'

I would expect that all CRUD statements would be logged to log_filename.
However CRUD statements called from trigger functions are not logged.

This is unexpected, and does not reflect my reading of the documentation.