I have another solution for this problem.Into a Vertical panel inserted horisontal panel formatted it with css, and it is faster..
2009/2/19 milind <[email protected]> > > Hi Nick, > > Flex table is pretty slow if you want to display 50+ rows in it at a > time based on our experience. The slowness also varies for each > browser, only realistic way of getting around this problem is to > implement pagination, where you display only 20-30 rows on each page > and then provide links on the header to navigate through the pages. > > This way i am able to manage a display of thousands of records in less > than 500 milliseconds across the browsers (FF and chrome faster then > IE). > The application has many views with this approach displaying simple > tabluar data and also hierarchical data structures. > For displaying hierarchical data structures i initially went with > Tree, but that was pretty slow for large no. of rows, so i simulated > tree inside FlexTable using Click listener on (+/-) images. > This works like a charm. > > Regards, > Milind > > On Feb 18, 4:21 pm, Nick <[email protected]> wrote: > > Ok, Results > > What I’m finding is that the Grid does beat the FlexTable, but not by > > much with a small data set. Larger sets seem to widen the gap. My > > guess for this is that since FlexTable has the ability to add rows > > (Grid is sized from the start) that it works much like how other > > resizable constructs work such as Java’s ArrayList. My reasoning for > > this is that the first time the test is run the speed is very slow on > > the FlexTable (especially in IE). Repeated test runs after the > > initial are faster and I think this is because the table was being > > sized the first time as rows were added, and didn’t need to be resized > > during the following tests. > > > > The other thing I’m finding is that performace varies based on > > browser. I’m seeing FF run reasonably well. With IE the Grid runs > > about the same as FF but the FlexTable runs considerably slower. I > > also tested Opera and was stunned as it blew both others out of the > > water. > > > > My full write up is here with times and a test application you can run > > in your browser. > http://whatwouldnickdo.com/wordpress/401/performance-grid-vs-flextable/ > > > > On Feb 18, 2:10 pm, Nick <[email protected]> wrote: > > > > > Thanks for the response, I think you're correct. And it makes sense > > > that adding rows dynamically would account for the increase in time as > > > the row count is higher. > > > I'm going to run a few tests, and I'll post anything I find to this > > > post. > > > > > On Feb 18, 3:09 am, Alexey_Tsiunchik <[email protected]> > > > wrote: > > > > > > Hello Nick, > > > > > > Exactly the same issue was in our app. We need to display big lists > > > > (100 - 500) records, and FlexTable seems not solution for this. > > > > > > The problem is that FlexTable always checks table bounds (row number, > > > > column number) and when you put some value in FlexTable it performs > > > > checking for bounds, moreover it not store the colnum and rownum in > > > > some variables, but always calculate them dynamically. Moreover it > > > > dynamocally adds new rows. > > > > Thats why it becomes slower when number of rows increase. > > > > > > We had decided to use Grid rather then FlexTable. We can specify Grid > > > > bounds right after creation, and while we put data in cells in the > > > > cycle its performance remains the same for different grid size (here > I > > > > mean speed of adding row). > > > > > > But it also has it's disadvantages. When we need to display another > > > > data in the same Grid, and this data has different number of rows, > > > > we should call Grod.resize(int, int). And for > > > > big grids, this operation is very slow in IE (in our tests resizing > > > > grid with 200 rows, 5 columns, takes ~13000 ms in IE). > > > > > > So It seems paging here the only solution. > > > > > > Tuesday, February 17, 2009, 6:40:51 PM, you wrote: > > > > > > > Ok, I did some more testing and I was wrong. It's not the > inserting > > > > > and removing from lists that are the bottleneck. I moved the time > and > > > > > log statements around and it had to do with adding to the FlexTable > > > > > itself. > > > > > I'm using code like: > > > > > int row = 1; > > > > > for (Iterator<MyData> iter = eventList.iterator(); iter.hasNext(); > row+ > > > > > +) { > > > > > long sysTime = System.currentTimeMillis(); > > > > > int column = 0; > > > > > MyData event = (MyData)iter.next(); > > > > > table.setText(row, column, event.getNameLast()); > > > > > column++; > > > > > table.setText(row, column, event.getNameFirst()); > > > > > column++; > > > > > table.setText(row, column, event.getJob()); > > > > > column++; > > > > > GWT.log("update time 4: > "+(System.currentTimeMillis()-sysTime)+"ms > > > > > ", null); > > > > > } > > > > > Now, you can see I'm logging the time after every row is inserted. > > > > > The odd thing I'm seeing is that the time per row increase as rows > are > > > > > traversed. For example, row 1 takes about 30ms but as the rows > > > > > traverse by row 100 each row is taking about 150ms. It's a steady > > > > > increase. > > > > > Any insights? > > > > > > -- > > > > Best regards, > > > > Alexey_Tsiunchik mailto: > [email protected] > > > -- Best Regards Tóth Imre --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/Google-Web-Toolkit?hl=en -~----------~----~----~----~------~----~------~--~---
