What I would like to do is:
instantiate store -> call fetch to get the data -> at a later time, run queries on this already populated store to return by a particular attribute in the store.

For instance, this will populate the store:

var store = new dojo.data.ItemFileReadStore({jsId:"cacheFirst",
                   url:"getCache.php?test_ids="+test_ids+"&page_id="+page_id+"&min_time=first&max_time=first&order=ASC&limit="+limit });
     var processCache = function(items,request){
       cache_first = items;

       /* default to the first item */
       cache_current = cache_first;
       cache_prev = null;
       updatePage();
     }
     store.fetch({onComplete:processCache});

I then would like to at a different time do:

store.query("get all payload_time=1000000");

Where the above code would simply return all the items in the store where payload_time=1000000.

I can certainly do this iteratively, but I assume the is some function that will do this for me already that I have not found. Now keep in mind that when I originally fetch the data, it is a pretty hefty SQL query, and that is why I want to return the data in one chunk, then do the filtering after. The store will be used as a cache, so as a button is clicked it will go to the next set of items, but the next set of items needs to be returned by this payload_time.

Any help will be greatly appreciated. Hopefully this is an easy one, and someone will just say, "look stupid, just use this function".

Dave