Preparing to unpack .../libpq5_9.3.14-0ubuntu0.14.04_amd64.deb ...
Unpacking libpq5 (9.3.14-0ubuntu0.14.04) over (9.3.13-0ubuntu0.14.04) ...
Preparing to unpack .../postgresql-contrib-9.3_9.3.14-0ubuntu0.14.04_amd64.deb ...
Unpacking postgresql-contrib-9.3 (9.3.14-0ubuntu0.14.04) over (9.3.13-0ubuntu0.14.04) ...
Preparing to unpack .../postgresql-client-9.3_9.3.14-0ubuntu0.14.04_amd64.deb ...
Unpacking postgresql-client-9.3 (9.3.14-0ubuntu0.14.04) over (9.3.13-0ubuntu0.14.04) ...
Preparing to unpack .../postgresql-9.3_9.3.14-0ubuntu0.14.04_amd64.deb ...
 * Stopping PostgreSQL 9.3 database server        
[ OK ]
Unpacking postgresql-9.3 (9.3.14-0ubuntu0.14.04) over (9.3.13-0ubuntu0.14.04) ...
Processing triggers for postgresql-common (154ubuntu1) ...
Building PostgreSQL dictionaries from installed myspell/hunspell packages...
  en_au
  en_gb
  en_us
  en_za
Removing obsolete dictionary files:
Setting up libgcrypt11:amd64 (1.5.3-2ubuntu4.4) ...
Setting up libgcrypt11:i386 (1.5.3-2ubuntu4.4) ...
Setting up libpq5 (9.3.14-0ubuntu0.14.04) ...
Setting up postgresql-client-9.3 (9.3.14-0ubuntu0.14.04) ...
Setting up postgresql-9.3 (9.3.14-0ubuntu0.14.04) ...
 * Starting PostgreSQL 9.3 database server         * The PostgreSQL server failed to start. Please check the log output:
2016-08-19 15:28:26 GMT LOG:  loaded library "pg_stat_statements"
2016-08-19 15:28:26 GMT LOG:  loaded library "auto_explain"
2016-08-19 15:28:26 GMT FATAL:  could not map anonymous shared memory: Cannot allocate memory
2016-08-19 15:28:26 GMT HINT:  This error usually means that PostgreSQL's request for a shared memory segment exceeded available memory or swap space. To reduce the request size (currently 1137074176 bytes), reduce PostgreSQL's shared memory usage, perhaps by reducing shared_buffers or max_connections.

[fail]
invoke-rc.d: initscript postgresql, action "start" failed.