Inserts of stateless session of NHibernate are slow

Question

It's been a couple of days that I'm working on improving NHibernate Insert performance.

I'd read in many posts (such as this one) that stateless session can insert like 1000~2000 records per second.... However the best time that it could insert 1243 records is more than 9 seconds for me :

var sessionFactory = new NHibernateConfiguration().CreateSessionFactory();
using (IStatelessSession statelessSession = sessionFactory.OpenStatelessSession())
{
   statelessSession.SetBatchSize(adjustmentValues.Count);

   foreach (var adj in adjustmentValues)
      statelessSession.Insert(adj);
}

The class :

public partial class AdjustmentValue : PersistentObject, IFinancialValue
{
    public virtual double Amount { get; set; }
    public virtual bool HasManualValue { get; set; }
    public virtual bool HasScaleValue { get; set; }
    public virtual string Formula { get; set; }
    public virtual DateTime IssueDate { get; set; }

    public virtual CompanyTopic CompanyTopic { get; set; }
}

Map of the class :

public class AdjustmentValueMap : ClassMap<AdjustmentValue>
{
    public AdjustmentValueMap()
    {
       Id(P => P.Id);

       Map(p => p.Amount);
       Map(p => p.IssueDate);
       Map(p => p.HasManualValue);
       Map(p => p.HasScaleValue);
       Map(p => p.Formula);

       References(p => p.CompanyTopic)
           .Fetch.Join();
    }
}

Am I missing something? Any idea how to speed up the inserts?

The generated queries will be same as below :

Answer 1

from the looks of your NHProf results you are using identity as your POID. Therefore you cannot take advantage of batched writes. every insert/update/delete is a separate command. that is why it's taking so long.

if you change your POID to hilo, guid or guid.comb and set the batch size to 500 or 1000 then you will see a drastic improvement in the write times.