PHP Version 5.3.3 on CentOS (x86_64, RHEL 6)
Apparently my PHP installation was configured to exclude Mysqli and disable PDO for some reason. Therefore, I believe th
mysqli is provided by php-mysql-5.3.3-40.el6_6.x86_64
You may need to try the following
yum install php-mysql-5.3.3-40.el6_6.x86_64
You might just have to install the packages.
yum install php-pdo php-mysqli
After they're installed, restart Apache.
httpd restart
or
apachectl restart