JSF: error handling with and JSF1073 error

First, let's compare apples with apples: Reads and writes with MongoDB are like single reads and writes by primary key on a table with no non-clustered indexes in an RDBMS.

So lets benchmark exactly that: http://mysqlha.blogspot.de/2010/09/mysql-versus-mongodb-yet-another-silly.html

And it turns out, the speed difference in a fair comparison of exactly the same primitive operation is not big. In fact, MySQL is slightly faster. I'd say, they are equivalent.

Why? Because actually, both systems are doing similar things in this particular benchmark. Returning a single row, searched by primary key, is actually not that much work. It is a very fast operation. I suspect that cross-process communication overheads are a big part of it.

My guess is, that the more tuned code in MySQL outweighs the slightly less systematic overheads of MongoDB (no logical locks and probably some other small things).

This leads to an interesting conclusion: You can use MySQL like a document database and get excellent performance out of it.

If the interviewer said: "We don't care about documents or styles, we just need a much faster database, do you think we should use MySQL or MongoDB?", what would I answer?

I'd recommend to disregard performance for a moment and look at the relative strength of the two systems. Things like scaling (way up) and replication come to mind for MongoDB. For MySQL, there are a lot more features like rich queries, concurrency models, better tooling and maturity and lots more.

Basically, you can trade features for performance. Are willing to do that? That is a choice that cannot be made generally. If you opt for performance at any cost, consider tuning MySQL first before adding another technology.

Here is what happens when a client retrieves a single row/document by primary key. I'll annotate the differences between both systems:

1. Client builds a binary command (same)
2. Client sends it over TCP (same)
3. Server parses the command (same)
4. Server accesses query plan from cache (SQL only, not MongoDB, not HandlerSocket)
5. Server asks B-Tree component to access the row (same)
6. Server takes a physical readonly-lock on the B-Tree path leading to the row (same)
7. Server takes a logical lock on the row (SQL only, not MongoDB, not HandlerSocket)
8. Server serializes the row and sends it over TCP (same)
9. Client deserializes it (same)

There are only two additional steps for typical SQL-bases RDBMS'es. That's why there isn't really a difference.

Firstly, you have to know about kind of scopes:

• Request.
• View.
• Session.
• Application.

The scope is the time of life of your data, you must use only one, you have two scopes in your code:

@SessionScoped
@ViewScoped

I recommend you to use ViewScoped, but you think about how much time you want your data live, if you choose ViewScoped, your data would live while you don't change the view or the page, if you choose SessionScoped, your data would live while you don't logout.

Now, you have to update the list of your table. You have:

<p:dataTable id="dataTableTeszt" value="#{TesztBean.values}" var="c" paginator="true" rows="25" editable="true" filteredValue="#{TesztBeanBean.filteredOsszesito}" scrollable="true" scrollWidth="1500" scrollHeight="550"
                        paginatorTemplate="{CurrentPageReport}  {FirstPageLink} {PreviousPageLink} {PageLinks} {NextPageLink} {LastPageLink} {RowsPerPageDropdown}"  
                        paginatorPosition="bottom" rowsPerPageTemplate="5,10,15,20,30,40,50" 
                        selectionMode="multiple" selection="#{TesztBean.selectList}" rowKey="#{c.id}">

The main list of your table is values value="#{TesztBean.values}", when you call to update method, you have to update your values list:

public void update(RowEditEvent event) {

        TesztSetGet edittedObject = (TesztSetGet) event.getObject();        

        Connection connection = null;
        PreparedStatement pst = null;
        ResultSet rs = null;

        String sql = "update teszt set kapcsolatfelvetel_megtortent=?, levelkuldes_datuma=?, kepzes_kezdete=?, kepzes_vege=?, megjegyzes=?  where id=?";

        try{

            connection = getDBConnection();                                                                       
            pst = connection.prepareStatement(sql);



            pst.setString(1, edittedObject.getKapcsolatfelvetel_megtortent());
            pst.setString(2, edittedObject.getLevelkuldesenek_datuma());
            pst.setString(3, edittedObject.getKepzes_kezdete());
            pst.setString(4, edittedObject.getKepzes_vege());
            pst.setString(5, edittedObject.getMagyarazat());
            pst.setInt(6, edittedObject.getId());

            pst.executeUpdate();
            pst.close();
            connection.close();

            //UPDATE VALUES LIST WITH NEW DATA

        }catch(SQLException se){
            se.printStackTrace();
            se.getMessage();
         }catch(Exception e){
             e.printStackTrace();
             e.getMessage();
         }    


    }

I don't know how you can do it, but you can see the primefaces website, there are some samples about this, the idea is to update the main list of your table, values list in your case.

I hope this information helps you.

Good luck.

PS. If my english is bad, I am willing to receive comments. =P