实体框架6.1.3 ASP.Net异步数据库调用比同步慢得多

Question

我正在用Include测试数据库调用，并注意到与同步代码相比，我的async代码运行得非常慢。鉴于同步代码快了将近五倍，我假设我做错了非常严重的事情，但我找不到它。查看代码时，我似乎正在等待ToListAsync()，它应该是正确的。我在做什么错或者这是正常行为？

注意：按比例缩小示例仅关注一个数据库调用，示例中async是不必要的，但有时还是存在时差。

异步：

[HttpGet]
[Route("{bsid}/{caseId}/async")]
public async Task<IHttpActionResult> GetAsync(string bsid, int caseId)
{
    var db = new DbContext();

    var deviations = await db.RenewalCycles.Where(x => x.Deviations.Any())
        .Include(cycle => cycle.TPCase.CaseNames.Select(caseName => caseName.TPName))
        .Include(cycle => cycle.TPCase.CaseNames.Select(caseName => caseName.TPNameType))
        .Include(cycle => cycle.TPCase.GoodsAndServicesDescriptions)
        .Include(cycle => cycle.TPCase.RelatedCases.Select(relatedCase => relatedCase.TPCaseRelation))
        .Include(cycle => cycle.TPCase.RelatedCases.Select(relatedCase => relatedCase.TPCountry))
        .ToListAsync();

    return Ok();
}

同步：

[HttpGet]
[Route("{bsid}/{caseId}")]
public IHttpActionResult Get(string bsid, int caseId)
{
    var db = new DbContext();

   var deviations = db.RenewalCycles.Where(x => x.Deviations.Any())
        .Include(cycle => cycle.TPCase.CaseNames.Select(caseName => caseName.TPName))
        .Include(cycle => cycle.TPCase.CaseNames.Select(caseName => caseName.TPNameType))
        .Include(cycle => cycle.TPCase.GoodsAndServicesDescriptions)
        .Include(cycle => cycle.TPCase.RelatedCases.Select(relatedCase => relatedCase.TPCaseRelation))
        .Include(cycle => cycle.TPCase.RelatedCases.Select(relatedCase => relatedCase.TPCountry))
        .ToList();

    return Ok();
}