实体框架6和Async()性能

Question

我有一个关于实体框架6和ToListAsync()/ToList()的问题。

如果我有少量的数据(大约1000行)，我就会注意到ToListAsync()比ToList()快。

但是如果我有大量的数据(大约600.000行)，ToList()比ToListAsync()更快。

在这里你可以优化代码，有人可以解释为什么？

//SharedAnagra contains around 1000 rows
static List<SharedAnagra> GetSharedAnagraList()
{
    using (Intranet2k3Entities intranet2K3Entities = new Intranet2k3Entities())
    {
        List<SharedAnagra> listaSharedAnagras = (from a in intranet2K3Entities.sharedAnagra
                                                 select new SharedAnagra
                                                 {
                                                     AnagraActive = a.AnagraActive,
                                                     AnagraId = a.AnagraID,
                                                     AnagraName = a.AnagraName,
                                                     OfficeId = a.OfficeID
                                                 }).ToList();

        return listaSharedAnagras;
    }
}

static async Task<List<SharedAnagra>> GetSharedAnagraListAsync()
{
    using (Intranet2k3Entities intranet2K3Entities = new Intranet2k3Entities())
    {
        List<SharedAnagra> listaSharedAnagras = await (from a in intranet2K3Entities.sharedAnagra
                                                       select new SharedAnagra
                                                       {
                                                           AnagraActive = a.AnagraActive,
                                                           AnagraId = a.AnagraID,
                                                           AnagraName = a.AnagraName,
                                                           OfficeId = a.OfficeID
                                                       }).ToListAsync();

        return listaSharedAnagras;
    }
} 


//sharedAnagraNDGClienti contains 950000 rows
static List<SharedAnagraNdgClienti> ListaSharedNdgClienti()
{
    using (Intranet2k3Entities intranet2K3Entities = new Intranet2k3Entities())
    {
        List<SharedAnagraNdgClienti> lista = (from a in intranet2K3Entities.sharedAnagraNDGClienti
                                              select new SharedAnagraNdgClienti
                                              {
                                                  Cm = a.CM,
                                                  CodFisc = a.CodFisc,
                                                  Cognome = a.Cognome,
                                                  Descrizione = a.Descrizione,
                                                  FilialePrevalente = a.Filiale_Prevalente,
                                                  Ndg = a.NDG,
                                                  Nome = a.Nome,
                                                  Telefono = a.Telefono,
                                                  Tipologia = a.Tipologia,
                                                  Trae = a.TRAE,
                                                  Tsae = a.TSAE
                                              }).AsNoTracking().ToList();

        return lista;
    }
}

static async Task<List<SharedAnagraNdgClienti>> GetIssueTypeByIdAsync()
{
    List<SharedAnagraNdgClienti> listaSharedAnagraNdgClienti;

    using (Intranet2k3Entities intranet2K3Entities = new Intranet2k3Entities())
    {
        listaSharedAnagraNdgClienti = await (from a in intranet2K3Entities.sharedAnagraNDGClienti
                                             select new SharedAnagraNdgClienti
                                             {
                                                 Cm = a.CM,
                                                 CodFisc = a.CodFisc,
                                                 Cognome = a.Cognome,
                                                 Descrizione = a.Descrizione,
                                                 FilialePrevalente = a.Filiale_Prevalente,
                                                 Ndg = a.NDG,
                                                 Nome = a.Nome,
                                                 Telefono = a.Telefono,
                                                 Tipologia = a.Tipologia,
                                                 Trae = a.TRAE,
                                                 Tsae = a.TSAE
                                             }).AsNoTracking().ToListAsync();
    }

    return listaSharedAnagraNdgClienti;
}

Answer 1

我认为这不是你的query.This的问题，而是EF 6+框架本身的问题。我个人没有做过任何关于Asyn vc Sync.But的研发，我找到了一些关于that.Hope的有用的文章，对你有帮助。

什么时候真正使用异步？

在大多数使用异步的应用程序中，

不会有明显的好处，甚至可能是有害的。在提交之前，使用测试、分析和常识来衡量异步在您的特定场景中的影响。

下面是这篇文章：

这是一位Stackoveflow user.You能读懂too.Great one的人所做的伟大研究。