How to best keep track of loads of data

I know. .the subject blows. I couldn’t think of what to name the thread.

Basically I have an application where a lot of strings are being sent… There are 1-10 “main categories” and then subcats.

(ie: {“name”,“john”}, {“age”,“25”}, {“name”,“matt”} etc…);

What would be the best (and fastest) way of keeping track of these, and being able to sort through them in a decent way? Objects was where I started but after googling a bit it seems Objects in AS3 are among the slowest datatypes available.

Thanks for any advice. And those name/age thing are just examples btw ; )