As Chris Jones mentions in his latest post to his OTN blog, there's a tutorial that's been posted by David Felcey showing how to get started with Oracle Coherence via the memcached adapter in PHP. Coherence is Oracle's own version of a key/value storage that focuses on performance and scalability.
Coherence 12c (12.1.3) adds support for Memcached clients to directly store data a in Coherence cluster using the Binary Memcached protocol. This post outlines how to configure the Coherence Memcached Adaptor and includes a simple PHP example to show how Memecached clients can connect to a Coherence cluster.
He includes the XML configuration you'll need to create/modify on the Oracle side to make the memcached connections work and explains the different parts. With that in place, he moves on to the PHP example, showing a simple memcached request to store and retrieve a string. It's almost transparent to the PHP user save some of the configuration options required to make it work.