How does the Informix Client SDK relate to loading PHP extensions like php_pdo_informix.dll?

The Informix Client SDK is required to load PHP extensions like php_pdo_informix.dll, as it provides the necessary libraries and dependencies for PHP to communicate with an Informix database. To successfully load the php_pdo_informix.dll extension, you need to ensure that the Informix Client SDK is installed on the server where PHP is running.

// Enable the php_pdo_informix extension
extension=php_pdo_informix.dll