My web app has a large amount of data that needs random portions to be served by a PHP script. Because speed is of utmost importance, the data resides in RAM.

My web app has a large amount of data that needs random portions to be served by a PHP script. Because speed is of utmost importance, the data resides in RAM. I first built a working solution in PHP using IPC Shared Memory Segments and later ditched it in favour of PHP+Redis (you could use your own NoSQL datastore of choice of course). For me, it was way simpler/cleaner to implement and I got a bunch of features for free.