/usr/share/php5/pgsql/pdo_pgsql.ini is in php5-pgsql 5.5.9+dfsg-1ubuntu4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | ; configuration for php PostgreSQL module
; priority=20
extension=pdo_pgsql.so
|