Matlab and Fast Effficent Container Class

Hi,

I need to store data from a market data source in a container which must be searched, updated frequently. I don't know the number of rows ahead of time, so I can't accurately pre-allocate it (although I can make an accurate guess).

What's the best Matlab container class for this purpose? Is there a Hash Map?

Map Containers?

http://www.mathworks.com/help/matlab/map-containers.html