Appending data to PrimeFaces' dataTable using Ajax - ajax

Question

I'm trying to use another way of pagination in PrimeFaces' DataTable.
What I want to do is that new pages are shown "vertically", so the new loaded data has to be appended at the end of the previous DataTable.
Something like Facebook's home stream, in which clicking "Load old posts" will make them appear under the newest one.
Is this possible??
I've tried almost everything using paginator, but seems like there's no way to build a "vertical" dataTable.
If not with PrimeFaces, is there any component that does what I need?
The loading should be lazy, so, everytime that the user decides to load the new data, a query must be executed. No lists or something!
Thanks :)
EDIT:
JSF Page
<pou:dataTable scrollable="true" liveScroll="true" scrollHeight="400" scrollRows="100" value="#{postListBean_1.posts}" var="post">
<pou:column>
#{post.testo}
<hr/>
</pou:column>
</pou:dataTable>
BEAN
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package ManagedBeans;
import ejb.PostManagerLocal;
import entity.Post;
import java.io.Serializable;
import java.util.List;
import javax.annotation.PostConstruct;
import javax.ejb.EJB;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.RequestScoped;
/**
* La classe si occupa di gestire lo scambio di messaggi tra utenti. Da
* implementare ancora i metodi per l'invio e per la segnalazione dell'avvenuta
* lettura.
*
* #author stefano
*/
#ManagedBean
#RequestScoped
public class PostListBean_1 implements Serializable {
#EJB
private PostManagerLocal postManager;
private List<Post> posts;
private int limit = 0;
/**
* Get the value of posts
*
* #return the value of posts
*/
public List<Post> getPosts() {
limit+=4;
makePosts();
return posts;
}
/**
* Set the value of posts
*
* #param posts new value of posts
*/
public void setPosts(List<Post> posts) {
this.posts = posts;
}
/**
* Creates a new instance of PostListBean
*/
public PostListBean_1() {
}
/**
* Inizializza la lista dei posts, prendendoli in ordine inverso, in modo da
* avere prima i più recenti
*/
#PostConstruct
public void makePosts() {
int[] range = {0, limit};
posts = postManager.findRangeReverse(range);
}
}