Back when I was at Adobe, I had a demo which did paging with 60K records in the query being scrolled. It probably could have done more if I tried since it was doing everything incrementally, though I'll admit the experience was not perfect, particularly if you moved the thumb too quickly.
This was using the DataService with LCDS on the backend but it would be the same client code with "client data management" in flex builder. There were some tricks to deal with the big data sets: - paging automatically pages in objects but never releases the paged in objects by default. You can add this manually with the releaseItemsFromCollection method. You put this into a scroll event handler, periodically (but not too often) releasing any invisible data. - keeping the page request queue from getting too large. This was one problem I never solved completely... as you move the thumb, the data grid can request pages faster than they can be filled/released. There should be a way to either limit the page requests or keep them in a queue that can be flushed if you call the release method. I did a quick google search on "releaseItemsFromCollection" and it looks like the code from my demo made it into the LCDS docs. Not sure that even with this call it will do what you want but without that release call, the automatic paging stuff would eventually just keel-over from having too much in-memory. If that seems like the major problem, it might be worth trying it out. Jeff On Sun, Mar 14, 2010 at 11:28 AM, iloveyouwisconsin < [email protected]> wrote: > > > Maybe I'll have to wait until Flex 7 (or later) 'til they truly make flex > able to handle large datasets smoothly. (I guess I'll also have to advise > those at Adobe and the flex evangelists that what they define as a "large" > dataset isn't large in practice. They probably need to moonlight as interns > for a few of their customers to snapback into reality. There's no company in > the real world that would define a large dataset as only a few thousand > items) > > --- In [email protected] <flexcoders%40yahoogroups.com>, > "iloveyouwisconsin" <iloveyouwiscon...@...> wrote: > > > > How many records is considered "too large" for a datagrid to handle? I am > using Flex 4 with Zend AMF & paging enabled. When I google it the topic, > most seem to think that a "few thousand" is large, but that doesn't seem > hardly anything to me. I thought Zend would do the trick but it isn't > anywhere near what I need. My 15 million records didn't go over too well (I > can use the scroll wheel on my mouse to scroll through the records but it > kept crashing when I tried to use the scrollbar on the datagrid to jump > around). I ask because I don't want to have to jimmy around with code until > I'm blue in the face trying to find something flex can handle. Can I do 1 > million? 5,000? 500,000? I just want to be able to let users play around w/ > the scrollbar on the datagrid without it crashing, is all (though I realize > that the user's machine will play a big factor in performance. All of my > users have computers that are no more than a couple yrs old) > > > > I also ask because I am sure others would like to know for their > projects....is there a more efficient way to get the data than Zend, like > Livecycle or Coldfusion? I am willing to switch the backend up a bit in > order to increase performance of my app. > > > > > > many thanks! > > > > >
