An easy way to install in ubuntu(debain)
Just run " apt-get install php5-pgsql "
Con el fin de habilitar el soporte de PostgreSQL, --with-pgsql[=DIR] es requerido cuando se compila PHP. DIR es el directorio base donde está instalado PostgreSQL, por defecto generalmente es /usr/local/pgsql en sistemas linux. Si el módulo de objetos compartidos está disponible, el módulo PostgreSQL puede ser cargado usando la directiva extension en php.ini o la función dl().
On PHP 5.3, you may encounter this error.
Cannot create new link. Too many open links
I did with Archlinux. pgsql.so was active.
To resolve the issue, I had to active pdo.so and pdo_pgsql.so. Hope this helps!
On a Windows server, configured with Apache, adding the following line to httpd.conf to load libpq.dll can save you a lot of time :
LoadFile "C:/Program Files/PostgreSQL/8.4/bin/libpq.dll"
Note that you will have to change your folder accordingly to the installation path and version of PostgreSQL you have installed. Also note that having Apache and PostgreSQL on the same server for production environments is not recommended.
If you chose NOT TO replace the newer (>5.2.6) php_pgsql.dll with the old one (from 5.2.5) as mentioned in the note above, then libpq.dll must be available in your PATH.
Also note that the libpq.dll that comes with your installation of PostgreSQL will not work. You have to use the one available here:
Place the extracted dll in your php root directory (where php.exe resides)
Windows users should be mindful that since 5.2.6 it seems that the version of php_pgsql.dll supplied is dynamically linked and requires libpq.dll.
The version supplied in 5.2.5 is statically linked and does not have this dependency, if you cannot load the Postgres extension grab php_pgsql.dll from the 5.2.5 distribution