This mysqlnd extension handle a query results cache, handled by the application, or transparently.

Pecl site: mysqlnd_qc

Documentation : Mysqlnd query result cache plugin

Fedora review : Review request #739367

Installation, after the switch from php-mysql to php-mysqlnd :

yum --enablerepo=remi install php-pecl-mysqlnd-qc

RPM are available for fedora >= 10 and EL >= 4.

EL-5 package are in remi-test (as php-mysqlnd).