You can also connect to PostgreSQL via a UNIX domain socket by leaving the host empty. This should have less overhead than using TCP e.g.:
$dbh = new PDO('pgsql:user=exampleuser dbname=exampledb password=examplepass');
In fact as the C library call PQconnectdb underlies this implementation, you can supply anything that this library call would take - the "pgsql:" prefix gets stripped off before PQconnectdb is called, and if you supply any of the optional arguments (e.g. user), then these arguments will be added to the string that you supplied... Check the docs for your relevant PostgreSQL client library: e.g.
If you really want, you can use ';'s to separate your arguments - these will just be converted to spaces before PQconnectdb is called.
(PECL PDO_PGSQL >= 0.1.0)
PDO_PGSQL DSN — Connecting to PostgreSQL databases
The PDO_PGSQL Data Source Name (DSN) is composed of the following elements, delimited by spaces or semicolons:
- DSN prefix
The DSN prefix is
The hostname on which the database server resides.
The port on which the database server is running.
The name of the database.
The name of the user for the connection. If you specify the user name in the DSN, PDO ignores the value of the user name argument in the PDO constructor.
The password of the user for the connection. If you specify the password in the DSN, PDO ignores the value of the password argument in the PDO constructor.
The bytea fields are returned as streams.
Example #1 PDO_PGSQL DSN examples
The following example shows a PDO_PGSQL DSN for connecting to a PostgreSQL database:
The DSN syntax shown here did not work for me, but this did:
$dbh = new PDO("pgsql:dbname=$dbname;host=$host", $username, $password );
As opposed to
$dbh = new PDO('pgsql:dbname=$dbname;
Which makes sense and is more PGSQL standard.