Cached Data, Updatable ResultSets

[Gregg Bolinger]

I have a concern over using Cached Data and/or Updatable ResultSet (which is a form a cached data I suppose).
How can you possbily ensure consistency on data using cached data and cached result sets with multiple users accessing and updating the database?
My approach has always been to get the data I need, and only what I need, modify it, update it, whatever, then be done with it until needed again. I then started looking into using cached data and updatable resultsets for performance issues, but the more I look into it, the more I don't understand how data can stay consitent and current with multiple users accessing the same data.
I realize there are isolation levels so I can lock tables etc, and I do use that but I only have tables locked for a split second at best when making a change or adding data. But if I lock a table then use cached data to manipulate, the table would be locked for a long period of time, would it not?
Anyone care to give me some advice/input on advantages to cached data as it seems to be the "to do" thing these days?
Thanks.