It’s hard to imagine pushing the limits of object oriented PHP so far that your web servers choke, but the truth is those limits are reached faster than you think. — Ryan Campbell

I’ve run into this problem a number of times myself, and always with regards to the example Ryan provides – a script that exports a large database table to a CSV. I didn’t realise that it was the object instantiation that was sucking up all the memory – although perhaps this seems obvious in retrospect.