AJAX creates 15 queries in db - primefaces

Question

I have a simple datatable with cell editing in primefaces. It works, but, first, does not create JavaScript message, second, it creates 15 identically queries to db. (i can see that in hibernate console)
Code is token from official site:
<h:form id="form">
<p:growl id="messages" showDetail="true"/>
<p:contextMenu for="clients" widgetVar="cMenu">
<p:menuitem value="Edit Cell" icon="ui-icon-search" onclick="clientsTable.showCellEditor();return false;"/>
<p:menuitem value="Hide Menu" icon="ui-icon-close" onclick="cMenu.hide()"/>
</p:contextMenu>
<p:dataTable id="clients" var="client" value="#{clientsBean.clients}" paginator="true" rows="5"
editable="true" editMode="cell" widgetVar="clientsTable">
<p:ajax event="cellEdit" listener="#{clientsBean.onCellEdit}" update=":form:messages"/>
<p:column headerText="Name" style="width:25%">
<p:cellEditor>
<f:facet name="output"><h:outputText value="#{client.name}"/></f:facet>
<f:facet name="input"><p:inputText id="nameInput" value="#{client.name}"
style="width:96%"/></f:facet>
</p:cellEditor>
</p:column>
So, when i edit some info and press Enter, it creates 15 queries and does not show JS message.
Bean's getClients() is a simple hibernate query (works fine), and onCellEdit() looks like
public void onCellEdit(CellEditEvent event) {
Object oldValue = event.getOldValue();
Object newValue = event.getNewValue();
if(newValue != null && !newValue.equals(oldValue)) {
FacesMessage msg = new FacesMessage(FacesMessage.SEVERITY_INFO, "Cell Changed", "Old: " + oldValue + ", New:" + newValue);
FacesContext.getCurrentInstance().addMessage(null, msg);
}
}
Also new strange bug apperead : oldValue and newValue in that bean are always same.