Sounds like you need to decouple the scrollbar from the list control so that you can set the scroll bar min/max values based upon the size of the dataset, which would have to be returned as metadata, independently of the entire dataset. You move the scrollbar, an rpc call is made, and a section of the dataset is returned and rendered. This would eliminate the memory hit from bringing over a huge dataset of AS objects in one shot. The latency over the wire shouldn't be too bad, because at any given time you're only requesting a small portion of the total records. No point in returning more records that the user can practically interact with at any one time.
See the VScrollBar control. Jeff ________________________________ From: flexcoders@yahoogroups.com [mailto:flexcod...@yahoogroups.com] On Behalf Of Alex Harui Sent: Tuesday, March 16, 2010 12:18 AM To: flexcoders@yahoogroups.com Subject: Re: [flexcoders] Re: Flex 4....Large recordset...how much is too much? Can you reproduce your problem in a simple test case? You say you aren't bringing down the full data set all at once so unless your data records are really big or you are trying to make the datagrid really "tall" so it can display without scrollbars, I wouldn't expect you to run out of memory. If you use up more than 500MB the Browser and Flash Player start getting creaky, but otherwise I would expect things to work. If you make the DG more than 8000 pixels tall, you can run into Flash Player limits. When you say crash is the Player/Browser crashing or are you getting a runtime exception? If you're getting an exception, what is the stack trace? On 3/15/10 4:32 PM, "iloveyouwisconsin" <iloveyouwiscon...@yahoo.com> wrote: We have a need for that in our project. I will say that much w/out giving away the idea. The question, though, is why is Flex (without hacks) limiting the amount of data we can view? The datagrid should be smarter than it is and in my opinion has a long way to go in order to be a truly viable means for data-intensive applications. Remember, I'm not VIEWING 15 million records at ONCE. I'm only retrieving 25 or 100 rows at a time from a database that is 15 million records. I want to give the user the OPTION of jumping around the database via moving the thumb around on the scrollbar...without crashing the application. As a workaround (at least in the short-term), how could I force the thumb icon to the bottom of the scrollbar after a user scrolls, like they do here: http://blog.tremend.ro/2009/03/02/flex-live-scroll-datagrid? I know that they have source enabled, but the switch to flex 4 (and paging enabled on my php service) would change the entire process, right? --- In flexcoders@yahoogroups.com <mailto:flexcoders%40yahoogroups.com> , "gmbroth" <gmbr...@...> wrote: > > I'm curious: what's the use case for pushing 15 million (or, heck, even > 50,000) records to the client? > > > --- In flexcoders@yahoogroups.com <mailto:flexcoders%40yahoogroups.com> , > "iloveyouwisconsin" <iloveyouwisconsin@> 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 flexcoders@yahoogroups.com <mailto:flexcoders%40yahoogroups.com> , > > "iloveyouwisconsin" <iloveyouwisconsin@> 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! > > > > > > -- Alex Harui Flex SDK Team Adobe System, Inc. http://blogs.adobe.com/aharui
