kogrid not updating column when data changed

[yozawiratama]

i have simple data like this :

var dataFromAjax = [
{Id : 1, Name : "Yoza", Status : 1},
{Id : 2, Name : "Dhika", Status : 1}
];

and next data from ajax will have different schema. like this :

var nextData = [
{Id : 1, Name : 'Yoza', Job : 'Programmer', Phone : '08788'},
{Id : 1, Name : 'Dhika', Job : 'Designer', Phone : '99987922'}
]

in my piece of code :

self.Data = ko.observableArray();
self.Data(nextData);
self.Data.valueHasMutated();

the problem is column not updated. column still same like first schema, that are id, name and status. Job and Phone not rendered. how to render different schema?