根据用户查询对结果进行排序的简单评级算法

Question

我正在开发一个非常基本的网络搜索引擎，它有几个部分。根据用户查询检索结果后，我想计算每个结果的比率，然后按计算得出的比率对结果进行排序。这里是我的查询：

var tmpQuery = (from urls in _context.Urls 
       join documents in _context.Documents 
        on urls.UrlId equals documents.DocumentId 
       let words = (from words in _context.Words 
          join hits in _context.Hits 
           on words.WordId equals hits.WordId 
          where hits.DocumentId == documents.DocumentId 
          select words.Text) 
       select new { urls, documents, words }); 

var results = (from r in tmpQuery.AsEnumerable() 
       where r.urls.ResolvedPath.Contains(breakedQuery, KeywordParts.Url, part) || 
        r.documents.Title.Contains(breakedQuery, KeywordParts.Title, part) || 
        r.documents.Keywords.Contains(breakedQuery, KeywordParts.Keywords, part) || 
        r.documents.Description.Contains(breakedQuery, Description, part) || 
        r.words.Contains(breakedQuery, KeywordParts.Content, part) 

        select new SearchResult() 
        { 
         UrlId = r.urls.UrlId, 
         Url = r.urls.ResolvedPath, 
         IndexedOn = r.documents.IndexedOn, 
         Title = r.documents.Title, 
         Description = r.documents.Description, 
         Host = new Uri(r.urls.ResolvedPath).Host, 
         Length = r.documents.Length, 
         Rate = 0CalculateRating(breakedQuery, r.urls.ResolvedPath, r.documents.Title, r.documents.Keywords, r.documents.Description, r.words) 
        }).AsEnumerable() 
        .OrderByDescending(result => result.Rate) 
        .Distinct(new SearchResultEqualityComparer()); 

和速率是通过这种方法计算：

private int CalculateRating(IEnumerable<string> breakedQuery, string resolvedPath, string title, string keywords, string description, IEnumerable<string> words) 
    { 
     var baseRate = 0; 

     foreach (var query in breakedQuery) 
     { 
      /*first I'm breaking up user raw query (Microsoft -Apple) to list of broken 
      queries (Microsoft, -Apple) if broken query start with - that means 
      results shouldn't have*/ 
      var none = (query.StartsWith("-")); 
      string term = query.Replace("-", ""); 

      var pathCount = Calculate(resolvedPath, term); 
      var titleCount = Calculate(title, term); 
      var keywordsCount = Calculate(keywords, term); 
      var descriptionCount = Calculate(description, term); 
      var wordsCount = Calculate(words, term); 

      var result = (pathCount * 100) + (titleCount * 50) + (keywordsCount * 25) + (descriptionCount * 10) + (wordsCount); 

      if (none) 
       baseRate -= result; 
      else 
       baseRate += result; 
     } 
     return baseRate; 
    } 

    private int Calculate(string source, string query) 
    { 
     if (!string.IsNullOrWhiteSpace(source)) 
      return Calculate(source.Split(' ').AsEnumerable<string>(), query); 
     return 0; 
    } 

    private int Calculate(IEnumerable<string> sources, string query) 
    { 
     var count = 0; 
     if (sources != null && sources.Count() > 0) 
     { 
      //to comparing two strings 
      //first case sensitive 
      var elements = sources.Where(source => source == query); 
      count += elements.Count(); 
      //second case insensitive (half point of sensitive) 
      count += sources.Except(elements).Where(source => source.ToLowerInvariant() == query.ToLowerInvariant()).Count()/2; 
     } 
     return count; 
    } 

请指引我以提高性能（我的搜索引擎的速度是非常非常低）

Answer 1

我期待这取决于您的from urls in _context.Urls - 没有哪个位置可以获得大量数据，然后在建立结果时丢弃。 tmpQuery /结果中有多少项目？