Question

I know that for multi part writes, I should be using transactions in nhibernate. However what about for simple read and writes (1 part) … I’ve read that it’s good practice to always use transactions. Is this required?

Should I do the following for a simple read ?? or can I just drop the transcaction part all togather ?

public PrinterJob RetrievePrinterJobById(Guid id)
{
    using (ISession session = sessionFactory.OpenSession())
    {
        using (ITransaction transaction = session.BeginTransaction())
        {
            var printerJob2 = (PrinterJob) session.Get(typeof (PrinterJob), id);
            transaction.Commit();

            return printerJob2;
        }
    }  
}

or

public PrinterJob RetrievePrinterJobById(Guid id)
{
    using (ISession session = sessionFactory.OpenSession())
    {
        return (PrinterJob) session.Get(typeof (PrinterJob), id);              
    }
}

What about for simple writes?

public void AddPrintJob(PrinterJob printerJob)
{
    using (ISession session = sessionFactory.OpenSession())
    {
        using (ITransaction transaction = session.BeginTransaction())
        {
            session.Save(printerJob);
            transaction.Commit();
        }
    }
}

Answer 1

Best recommendation would be to always use a transaction. This link from the NHProf documentation, best explains why.

When we don’t define our own
transactions, it falls back into
implicit transaction mode, where every
statement to the database runs in its
own transaction, resulting in a large
performance cost (database time to
build and tear down transactions), and
reduced consistency.

Even if we are only reading data, we
should use a transaction, because
using transactions ensures that we get
consistent results from the database.
NHibernate assumes that all access to
the database is done under a
transaction, and strongly discourages
any use of the session without a
transaction.

(BTW, if you are doing serious NHibernate work, consider trying out NHProf).