Is it possible to exclude specific users in log activity of PostgreSQL?
Using the ALTER ROLE ... SET parameter; command, it was possible to tailor user-specific log parameters. Note that the parameter only takes effect after logout.

Setting log_min_duration_statement=-1 (1st login):

psql console

P:\&gt;psql -U postgres -h 132.156.208.45 -d my_db

my_db=# SHOW log_min_duration_statement;
 log_min_duration_statement
----------------------------
 0
(1 ligne)

my_db=# SELECT COUNT(*) FROM organisms;
 count
-------
   153
(1 ligne)

my_db=# ALTER ROLE postgres SET log_min_duration_statement=-1;
ALTER ROLE

my_db=# SHOW log_min_duration_statement;
 log_min_duration_statement
----------------------------
 0
(1 ligne)

my_db=# SELECT COUNT(*) FROM mv_rings;
 count
--------
 115270
(1 ligne)

my_db=# \q


Result on the log:

Note that within that session, all statements are visible in the log even after setting log_min_duration_statement=-1.

2015-10-15 14:14:01 EDT [unknown] my_db 123.456.789.012 postgres |LOG:  connection authorized: user=postgres database=my_db
2015-10-15 14:14:08 EDT psql my_db 123.456.789.012 postgres |LOG:  duration: 0.000 ms  statement: SHOW log_min_duration_statement;
2015-10-15 14:15:26 EDT psql my_db 123.456.789.012 postgres |LOG:  duration: 32.000 ms  statement: SELECT COUNT(*) FROM organisms;
2015-10-15 14:15:45 EDT psql my_db 123.456.789.012 postgres |LOG:  duration: 31.000 ms  statement: ALTER ROLE postgres SET log_min_duration_statement=-1;
2015-10-15 14:16:08 EDT psql my_db 123.456.789.012 postgres |LOG:  duration: 0.000 ms  statement: SHOW log_min_duration_statement;
2015-10-15 14:17:10 EDT psql my_db 123.456.789.012 postgres |LOG:  duration: 2059.000 ms  statement: SELECT COUNT(*) FROM mv_rings;
2015-10-15 14:17:29 EDT psql my_db 123.456.789.012 postgres |LOG:  disconnection: session time: 0:03:27.450 user=postgres database=my_db host=123.456.789.012 port=65269


Seeing the effect of log_min_duration_statement (2nd login):

psql console

P:\&gt;psql -U postgres -h 132.156.208.45 -d my_db

my_db=# SHOW log_min_duration_statement;
 log_min_duration_statement
----------------------------
 -1
(1 ligne)

my_db=# SELECT COUNT(*) FROM germplasms;
 count
--------
 475290
(1 ligne)

my_db=# \q


Result on the log:

As expected none of the statements are logged.

2015-10-15 14:17:44 EDT [unknown] my_db 123.456.789.012 postgres |LOG:  connection authorized: user=postgres database=my_db
2015-10-15 14:20:27 EDT psql my_db 123.456.789.012 postgres |LOG:  disconnection: session time: 0:02:43.333 user=postgres database=my_db host=123.456.789.012 port=49372