Have anyone had performance issue when creating a select all / deselect all on the toolbar and the update is very slow. It took around 10 seconds to iterate through 300 records in the grid using the datasource set/get methods. 

The code I used is as follows:

```

    var data = dataSource.view();
    for (var idx = 0, length = data.length; idx < length; idx++) {
        if (!data[idx].IsActive) data[idx].set("IsActive", true);
    }

```

Anyone encountered this issue? Is there a way to improve the performance?

Thanks.