Enable pg_stat_statements

Hi all,

I have Postgres 9.3.2 running on Debian 7.

I would like to enable the pg_stat_statements extension. In order to do
this, I added the following line to postgresql.conf:

shared_preload_libraries = 'pg_stat_statements'

However after that the server fails to restart and I get the following
error message:

Restarting PostgreSQL 9.3 database server: mainThe PostgreSQL server
failed to start. Please check the log output: 2014-02-06 15:12:34 CET
FATAL: could not access file "pg_stat_statements": No such file or
directory ... failed!
  failed!

Any ideas why?

Thanks in advance!

S.