>XML5 has it, local cursors, that is, and now that MS appears to be shifting its ever so restless gaze away from Silverlight and towards XML5 (will this NEVER end?!?!) we have the promise of getting back at least some of the productivity and ease of use that Fox has had since, oh, early 80's. You'll probably have to wait until 2022 to start using it, though, because that's when W3C estimates the final XML5 specs to be nailed down.

Frankly, storing data on client side would be, IMHO, a workaround for poor web engineering.
Storing on the server has our preference.