Ajax update doesn’t work, when using filter on p:dataTable

After updating datatable you have to invoke it’s client side filter() method.

<p:dataTable widgetVar="dataTableWidgetVar" id="dataTable" var="row"
             value="#{bean.value}"
             filteredValue="#{bean.filteredValue}"
             paginator="true" rows="25" paginatorPosition="bottom"
             rowKey="${row.id}"
             editable="true">

<p:commandButton value="Save"
                 actionListener="#{bean.save}"
                 update=":form"
                 oncomplete="PF('dataTableWidgetVar').filter()"/>

For PrimeFaces versions older than 5, you should use

<p:commandButton value="Save"
                 actionListener="#{bean.save}"
                 update=":form"
                 oncomplete="dataTableWidgetVar.filter()"/>