Sto riscontrando un comportamento strano dalla memorizzazione nella cache di Nhibernate e non riesco a capire il ragionamento. Io non sono in grado di memorizzare nella cache le query quando facendo operazioni di selezione comeproblema di nibernazione della cache con le query di linq
query.Select(x=>x).ToList()
ma può memorizzare nella cache quando si fa:
var query = session.Linq<Promoter>();
var p = query.ToList();
Entrambi producono la stessa query SQL e deve essere doign la stessa cosa. Il seguente test spiega il problema.
[Test]
public void Can_Use_Cache()
{
ISessionFactory factory = Storage.Application.Get<ISessionFactory>("SessionFactory");
// initial hit on the database and load into cache - all fine
using (var session = factory.OpenSession())
{
Console.WriteLine("");
Console.WriteLine("First Query");
var query = session.Linq<Promoter>();
query.QueryOptions.SetCachable(true);
query.QueryOptions.SetCacheMode(CacheMode.Normal);
var p = query.ToList();
}
// no hit on the database and retrieved from cache as expected - all fine
using (var session = factory.OpenSession())
{
Console.WriteLine("");
Console.WriteLine("Second Query");
var query = session.Linq<Promoter>();
query.QueryOptions.SetCachable(true);
query.QueryOptions.SetCacheMode(CacheMode.Normal);
var p = query.ToList();
}
// hits the db - should have come from the cache - not working
using (var session = factory.OpenSession())
{
Console.WriteLine("");
Console.WriteLine("Third Query");
var query = session.Linq<Promoter>();
query.QueryOptions.SetCachable(true);
query.QueryOptions.SetCacheMode(CacheMode.Normal);
var p = query.Select(x=>x).ToList();
}
// hits the db again - should have come from the cache - again not working
using (var session = factory.OpenSession())
{
Console.WriteLine("");
Console.WriteLine("Fourth Query");
var query = session.Linq<Promoter>();
query.QueryOptions.SetCachable(true);
query.QueryOptions.SetCacheMode(CacheMode.Normal);
var p = query.Select(x => x).ToList();
}
}
I risultati del mio test mostrano l'hit sul db per la seconda query. interroga 3 e 4 non deve essere colpendo il db:
2010-02-28 12:05:23,046 INFO Started Logging
First Query
2010-02-28 12:05:23,156 DEBUG SELECT this_.Id as Id11_0_, this_.Version as Version11_0_, this_.Name as Name11_0_ FROM Promoters this_
NHibernate: SELECT this_.Id as Id11_0_, this_.Version as Version11_0_, this_.Name as Name11_0_ FROM Promoters this_
Second Query
Third Query
2010-02-28 12:05:23,315 DEBUG SELECT this_.Id as Id11_0_, this_.Version as Version11_0_, this_.Name as Name11_0_ FROM Promoters this_
NHibernate: SELECT this_.Id as Id11_0_, this_.Version as Version11_0_, this_.Name as Name11_0_ FROM Promoters this_
Fourth Query
2010-02-28 12:05:23,318 DEBUG SELECT this_.Id as Id11_0_, this_.Version as Version11_0_, this_.Name as Name11_0_ FROM Promoters this_
NHibernate: SELECT this_.Id as Id11_0_, this_.Version as Version11_0_, this_.Name as Name11_0_ FROM Promoters this_
La cache è configurato utilizzando fluente:
SessionFactory = Fluently.Configure()
.Database(MsSqlConfiguration.MsSql2008
.ConnectionString(ConfigurationService.SqlConnectionString)
.ShowSql()
.Cache(c => c
.UseQueryCache()
.ProviderClass(typeof(NHibernate.Cache.HashtableCacheProvider).AssemblyQualifiedName))
)
.Mappings(m => m.FluentMappings.AddFromAssemblyOf<EventMap>()
.Conventions.Setup(MappingConventions.GetConventions()))
.ExposeConfiguration(BuildSchema)
.BuildSessionFactory();