How i got more performance in basex?

Question

Actually i have a basex collection with 15000 registries, i'm implementing a jsf and basex aplication, but i got a issue with the performance of the queries, actually i'm using JAXB to convert the xml into objects in java, but is very slow, this is how i do the basex queries:

public class AssetDao implements Dao<Asset>{
public static AssetDao instance;
private String db ="deterioro";
private String assetsModule = "import module namespace assets='http://creativosdigitales.co/cartera/assets' at 'C:/Users/santiago umaña/Google Drive/Deterioro/xquery/assets.xqm';";
private String simulationsModule = "import module namespace simulations='http://creativosdigitales.co/cartera/simulations' at 'C:/Users/santiago umaña/Google Drive/Deterioro/xquery/simulations.xqm';";

public static AssetDao getInstance() {
    if(instance == null) {
        instance = new AssetDao();
    }
    return instance;
}

@Override
public List<Asset> get() throws IOException, JAXBException {
    List<Asset> results = new ArrayList<Asset>();
    try(BaseXClient session = new BaseXClient("localhost", 1984, "admin", "admin")){
        session.execute("open "+db);
        final String xquery = "for $data in subsequence(//asset, 1, 20) return <asset> {$data/assetid} {$data/payment} {$data/pendingpayments} <balance>{ format-number($data/balance, \"#.00\") }</balance> <npv>{ format-number(sum(//simulation[assetid=$data/assetid]/payment/npv), \"#.00\") }</npv> <difference>{ format-number($data/balance - sum(//simulation[assetid=$data/assetid]/payment/npv), \"#.00\") }</difference> </asset>";
        JAXBContext context = JAXBContext.newInstance(Asset.class);
        Unmarshaller unmarshaller = context.createUnmarshaller();
        Query query = session.query(xquery);
        while(query.more()) {
            results.add((Asset) unmarshaller.unmarshal(new StringReader(query.next())));
        }
        return results;
    }
}

//custom methods
public List<ExtraField> getExtraFields(String assetId) throws IOException, JAXBException {
    List<ExtraField> extraFields = new ArrayList<ExtraField>();
    try(BaseXClient session = new BaseXClient("localhost", 1984, "admin", "admin")){
        final String xquery = assetsModule
                + "let $db := collection('"+db+"')"
                + "let $asset := assets:asset-info($db, '"+assetId+"')"
                + "return assets:extra-fields($asset)";
        JAXBContext context = JAXBContext.newInstance(ExtraField.class);
        Unmarshaller unmarshaller = context.createUnmarshaller();
        Query query = session.query(xquery);
        System.out.println(query.toString());
        while(query.more()) {
            extraFields.add((ExtraField) unmarshaller.unmarshal(new StringReader(query.next())));
        }
        return extraFields;
    }
}

public List<Simulation> getSimulation(String assetId) throws IOException, JAXBException {
    List<Simulation> simulations = new ArrayList<Simulation>();
    try(BaseXClient session = new BaseXClient("localhost", 1984, "admin", "admin")){
        final String xquery = assetsModule
                + simulationsModule
                + "let $db := collection('"+db+"')"
                + "let $asset := assets:asset-info($db, '"+assetId+"')"
                + "return simulations:simulation-xml($asset)";
        JAXBContext context = JAXBContext.newInstance(Simulation.class);
        Unmarshaller unmarshaller = context.createUnmarshaller();
        Query query = session.query(xquery);
        System.out.println(query.toString());
        while(query.more()) {
            simulations.add((Simulation) unmarshaller.unmarshal(new StringReader(query.next())));
        }
        return simulations;
    }
}

this is my xquery module:

module namespace assets='http://creativosdigitales.co/cartera/assets';

declare function assets:asset-list() 
{
  for $data in subsequence(//asset, 1, 100) 
  return 
  <asset> 
    {$data/assetid} 
    {$data/payment} 
    {$data/pendingpayments} 
    <balance>{ format-number($data/balance, "#.00") }</balance> 
    <npv>{ format-number(sum(//simulation[assetid=$data/assetid]/payment/npv), "#.00") }</npv> 
    <difference>{ format-number($data/balance - sum(//simulation[assetid=$data/assetid]/payment/npv), "#.00") }</difference> 
   </asset>
};

declare function assets:asset-info($collection, $assetid)
{
  <asset>
  { $collection/*/asset[assetid=$assetid]/*,
    $collection//simulation[assetid=$assetid],
    $collection//punishment[assetid=$assetid] }
  </asset>
};

declare function assets:extra-fields($info)
{
  let $standard := ('assetid','customerid','customername','amount','term','balance','default','rate','payment','pendingpayments', 'paidpayments', 'extrapayments', 'totalnpv', 'punishment', 'expectednpv', 'simulation', 'policy')
  for $x in $info/*[name() != $standard ]
  return
    <extrafield>
      <name>{ $x/name() }</name>
      <text>{ $x/text() }</text>
    </extrafield>
};

Actually loading 100 items takes some 2 or 3 mins, loading 20 items takes 20 secs, how do I get a better performance to get the items and parse into java objects?

pd: this is my java object:

@ManagedBean
@XmlRootElement(name="asset")
@XmlType(propOrder = {"assetid", "payment", "pendingpayments", "balance", "npv", "difference"})
public class Asset {
    private String assetid;
    private String payment;
    private String pendingpayments;
    private String balance;
    //net present value
    private String npv;
    //difference between balance and npv
    private String difference; 

    public Asset() {
        // TODO Auto-generated constructor stub
    }

    @XmlElement(name="assetid")
    public String getAssetid() {
        return assetid;
    }

    public void setAssetid(String assetid) {
        this.assetid = assetid;
    }

    @XmlElement(name="payment")
    public String getPayment() {
        return payment;
    }

    public void setPayment(String payment) {
        this.payment = payment;
    }

    @XmlElement(name="pendingpayments")
    public String getPendingpayments() {
        return pendingpayments;
    }

    public void setPendingpayments(String pendingpayments) {
        this.pendingpayments = pendingpayments;
    }

    @XmlElement(name="balance")
    public String getBalance() {
        return balance;
    }

    public void setBalance(String balance) {
        this.balance = balance;
    }

    @XmlElement(name="npv")
    public String getNpv() {
        return npv;
    }

    public void setNpv(String npv) {
        this.npv = npv;
    }

    @XmlElement(name="difference")
    public String getDifference() {
        return difference;
    }

    public void setDifference(String difference) {
        this.difference = difference;
    }
}