Thanks Alex. It is very useful or me also. I am in same scenario because i have created a custom grid that is being used in many pages of my project. columns and data are created in runtime as well. although i have created lightwet renderers to get optimize performance. but few things i learned here in your post are very useful. Thanks again :)
sachin dev Tripathi [email protected] Alex Harui wrote: > > 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 > > -- View this message in context: http://old.nabble.com/DataGrids-with-large-datasets-Tips---Tricks--tp27994256p28012708.html Sent from the FlexCoders mailing list archive at Nabble.com.
