How can i improve the performance of query task, suppose if i have to query for about 20-30 features , the browser will hang , what is the performance tuning approaches for ESRI.
If you are currently setting outFields to everything (query.outFields=["*"]) remove it and use outFields to specify only the fields you will be using in the query or results. If you aren't including the results of the query on the map then set query.returnGeometry to false.
Try those out and see if they improve performance. If not it would be helpful to see a code snippet showing what you are currently doing - and perhaps the url to your service if its publicly available.
Thanks kelly i was able to speed up the performance of the query task .I added the maxallowable and spatial reference but still can i improve performance when i try to query for more features i get esri.config.defaults.io.proxyUrl is not set error in IE
