BUG #14694: Long binded parameter value in the postgres log

The following bug has been logged on the website:

Bug reference: 14694
Logged by: Nikolay Nikitin
Email address: nikolay(dot)nikitin(at)infowatch(dot)com
PostgreSQL version: 9.6.3
Operating system: Red Hat Enterprise Linux Server release 6.7
Description:

Hi!

We insert many rows with long text and bytea (about 500 MB) values. In the
postgres config we set log_min_duration_statement to 120 seconds.
If this statements work more 120 seconds then they will be written into the
postgres log with parameter values.
As a result, the postgres log increases by 500MB for each statement.

I think the postgres should have a "max bind value size" parameter. If a
bind value is bigger then this parameter, it will be truncated.
And in the log its real size and its truncated part will be written.

Regards,
Nikolay.