I don’t have any particular links to recommend. Everything else is standard optimization techniques. Make sure your renderers have as few children as possible and are based on the lowest level class you can find. It is easy to use Canvas, Hbox and Vbox and many of our examples do, but they are very heavy and inefficient if you have lots of them on screen. None of the Flex default renderers are based on containers for that reason.
On 3/23/10 8:45 AM, "fusionpage" <[email protected]> wrote: Thanks Alex. This is very helpful and exactly in the direction of what I'm seeking to understand. I appreciate it. Have any recommended resources to learn more? Thanks, Don --- In [email protected] <mailto:flexcoders%40yahoogroups.com> , Alex Harui <aha...@...> wrote: > > It doesn't matter if you add columns at run-time or not. The main factor is > how many column you are displaying and how many rows will be displayed. And > note that is different from the total set of columns that could be displayed > and total number of data items: > > Example: I have a 10000 person database with 100 different statistics on > each person. I set up my DataGrid to have 100 columns representing each > statistic, but because it won't fit on the screen I set > horizontalScrollPolicy="true". Still, the DG is likely to be full screen so > it can show about 20 columns and 30 rows. > > Note that if do not set horizontalScrollPolicy="true", the DG will cram all > 100 columns on screen. This makes a significant difference. Instead of > 20x30=600 renderers, it is 100x30=3000 renderers. The DG will take more than > 5 times longer to set up and render 3000 renderers instead of 600 renderers, > memory usage will go way up, and even things like mouse tracking and CPU > utilization at idle time will be impacted. > > The next important thing to remember is that DG has a very generalized update > mechanism. If it detects a change to any of the 10000 person records, it > will refresh "all" of the renderers on the screen. It does not optimize for > whether that renderer is associated with that data item because > labelFunctions and custom renderers make it possible for any data item change > to affect every renderer. This is very inefficient, but we have to be this > conservative otherwise your renderers could miss updates. > > This is important in how you setup and maintain your dataProvider. A common > mistake I see is to take some XML, make a new ArrayCollection, and loop > through the XML creating Person records and using push/addItem to add it to > the ArrayCollection. Every time you do that, the AC generates a change > event, and if the DG is already bound, it is going to try to refresh all of > its renderers. > > So, aggregate changes. If you are converting XML, make an array, convert > items and push them on the array and then set the whole array into the > ArrayCollection's source. > > HTH, > > > On 3/22/10 4:28 PM, "fusionpage" <fusionp...@...> wrote: > > > > > > > > Does anyone have any tips or tricks, in general, about optimizing the Flex > client for best performance in populating/rendering large datasets in an > AdvancedDataGrid? > > I'm specifically NOT asking about improving the server-side. I'm trying to > understand what the factors are on the Flex client-side that impact how fast > data loads/renders into an ADG, when the columns use in-line itemrenderers > and/or the columns are added at run-time. > > Are there any significant difference in performance when comparing different > design patterns or ways of generating the datagrid? e.g. does it matter if it > generated via pure AS3, or if you use MXML? Is performance the same no matter > which design pattern one uses? > > Assume the data is loading via a RemoteObject call. In my case via a > ColdFusion CFC. > > Any tips, tricks, or links so I can learn more? > > So, far, in my experience, most of the performance issues come from the > server-side, but I may be ignorant on the impact of the design on the Flex > side. > > Thanks, > Don > > > > > > > -- > Alex Harui > Flex SDK Team > Adobe System, Inc. > http://blogs.adobe.com/aharui > -- Alex Harui Flex SDK Team Adobe System, Inc. http://blogs.adobe.com/aharui
