问较大型号的EF 6速度较慢问题

EN

public class DataAccess
{
    internal Model.Entities _ctx = null;
    private static DataAccess self = null;
    public object ModulePermission;

    private DataAccess()
    {
        var tmp = new ConnectionStringBuilder(Utility.GetConnectionString());
        _ctx = new Model.Entities(tmp.CaliberMatrixString);

        // temporarily dissabling the EF entity validation - it should be removed in the next code sync.
        _ctx.Configuration.ValidateOnSaveEnabled = false;
    }

    public static DataAccess Instance
    {
        get
        {
            var context = HttpContext.Current;
            if (context != null)
            {
                const string kApplicationSettings = "ApplicationObject";
                if (context != null && context.Items[kApplicationSettings] != null)
                {
                    var da = context.Items[kApplicationSettings] as DataAccess;
                    return da;
                }

                self = new DataAccess();
                context.Items[kApplicationSettings] = self;
            }
            else
            {
                self = new DataAccess();
            }
            return self;
        }
    }

    public void Save()
    {
        _ctx.SaveChanges();
    }

    internal Model.CaliberMatrixEntities Ctx { get { return _ctx; } }

    public void Dispose()
    {
        if (self != null)
        {
            //DataAccess.Instance.Dispose();
            const string kApplicationSettings = "ApplicationObject";
            var context = HttpContext.Current;
            if (context != null && context.Items[kApplicationSettings] != null)
                context.Items[kApplicationSettings] = null;
            _ctx.Dispose();
            _ctx = null;
            GC.SuppressFinalize(this);
            self = null;
        }
    }