RavenDb对以百万为单位的文档查询性能的期望

Question

我能够使用嵌入式版本的RavenDb加载几百万个文档，非常漂亮！

现在我试图查询这些项目，并发现性能不是我所期望的，如果可能的话，几乎是瞬间的，但是在一台相当健壮的机器上可以达到18秒。

下面，你会发现我的朴素代码。

注意：我现在已经解决了这个问题，最终的代码位于帖子的底部。带走的是你需要索引，它们必须是正确的类型，并且需要让RavenDB知道它们。非常满意通过查询引擎返回记录的性能和质量。

谢谢 斯蒂芬

using (var store = new EmbeddableDocumentStore { DataDirectory = @"C:\temp\ravendata" }.Initialize()) 
{ 
    using (IDocumentSession session = store.OpenSession()) 
    { 
     var q = session.Query<Product>().Where(x => x.INFO2.StartsWith("SYS")).ToList(); 
    } 
} 


[Serializable] 
public class Product 
{ 
    public decimal ProductId { get; set; } 
    .... 
    public string INFO2 { get; set; } 
} 

编辑

我加入这个类

public class InfoIndex_Search : AbstractIndexCreationTask<Product> 
{ 
    public InfoIndex_Search() 
    { 
     Map = products => 
      from p in products 
          select new { Info2Index = p.INFO2 }; 

     Index(x => x.INFO2, FieldIndexing.Analyzed); 
    } 
} 

，改变调用方法看起来像这样。

 using (var store = new EmbeddableDocumentStore { DataDirectory = @"C:\temp\ravendata" }.Initialize()) 
     { 
      // Tell Raven to create our indexes. 
      IndexCreation.CreateIndexes(Assembly.GetExecutingAssembly(), store); 

      List<Product> q = null; 
      using (IDocumentSession session = store.OpenSession()) 
      { 
       q = session.Query<Product>().Where(x => x.INFO2.StartsWith("SYS")).ToList(); 
       watch.Stop(); 
      } 
     } 

但我仍然报告18秒做搜索。我错过了什么？在另一个说明中，C：\ temp \ ravendata \ Indexes \ InfoIndex％2fSearch文件夹中有很多新文件，虽然不像插入数据时那么多，但它们在运行此代码后似乎都消失了几次尝试查询。如果IndexCreation.CreateIndexes（Assembly.GetExecutingAssembly（），store）;在插入之前调用，只有这样？

EDIT1

使用此代码我能得到查询的一个实例几乎要发生，但似乎你只能运行一次此，这样引出了一个问题。在哪里运行，什么是正确的初始化程序？

store.DatabaseCommands.PutIndex("ProdcustByInfo2", new IndexDefinitionBuilder<Product> 
{ 
    Map = products => from product in products 
         select new { product.INFO2 }, 
    Indexes = 
      { 
       { x => x.INFO2, FieldIndexing.Analyzed} 
      } 
}); 

EDIT2：工作示例

static void Main() 
{ 
    Stopwatch watch = Stopwatch.StartNew(); 

    int q = 0; 
    using (var store = new EmbeddableDocumentStore { DataDirectory = @"C:\temp\ravendata" }.Initialize()) 
    { 
     if (store.DatabaseCommands.GetIndex("ProdcustByInfo2") == null) 
     { 
      store.DatabaseCommands.PutIndex("ProdcustByInfo2", new IndexDefinitionBuilder<Product> 
      { 
       Map = products => from product in products 
            select new { product.INFO2 }, 
       Indexes = { { x => x.INFO2, FieldIndexing.Analyzed } } 
      }); 
     } 
     watch.Stop(); 
     Console.WriteLine("Time elapsed to create index {0}{1}", watch.ElapsedMilliseconds, System.Environment.NewLine); 

     watch = Stopwatch.StartNew();    
     using (IDocumentSession session = store.OpenSession()) 
     { 
      q = session.Query<Product>().Count(); 
     } 
     watch.Stop(); 
     Console.WriteLine("Time elapsed to query for products values {0}{1}", watch.ElapsedMilliseconds, System.Environment.NewLine); 
     Console.WriteLine("Total number of products loaded: {0}{1}", q, System.Environment.NewLine); 

     if (q == 0) 
     { 
      watch = Stopwatch.StartNew(); 
      var productsList = Parsers.GetProducts().ToList(); 
      watch.Stop(); 
      Console.WriteLine("Time elapsed to parse: {0}{1}", watch.ElapsedMilliseconds, System.Environment.NewLine); 
      Console.WriteLine("Total number of items parsed: {0}{1}", productsList.Count, System.Environment.NewLine); 

      watch = Stopwatch.StartNew(); 
      productsList.RemoveAll(_ => _ == null); 
      watch.Stop(); 
      Console.WriteLine("Time elapsed to remove null values {0}{1}", watch.ElapsedMilliseconds, System.Environment.NewLine); 
      Console.WriteLine("Total number of items loaded: {0}{1}", productsList.Count, System.Environment.NewLine); 

      watch = Stopwatch.StartNew(); 
      int batch = 0; 
      var session = store.OpenSession(); 
      foreach (var product in productsList) 
      { 
       batch++; 
       session.Store(product); 
       if (batch % 128 == 0) 
       { 
        session.SaveChanges(); 
        session.Dispose(); 
        session = store.OpenSession(); 
       } 
      } 
      session.SaveChanges(); 
      session.Dispose(); 
      watch.Stop(); 
      Console.WriteLine("Time elapsed to populate db from collection {0}{1}", watch.ElapsedMilliseconds, System.Environment.NewLine); 
     } 

     watch = Stopwatch.StartNew(); 
     using (IDocumentSession session = store.OpenSession()) 
     { 
      q = session.Query<Product>().Where(x => x.INFO2.StartsWith("SYS")).Count(); 
     } 
     watch.Stop(); 
     Console.WriteLine("Time elapsed to query for term {0}{1}", watch.ElapsedMilliseconds, System.Environment.NewLine); 
     Console.WriteLine("Total number of items found: {0}{1}", q, System.Environment.NewLine); 
    } 
    Console.ReadLine(); 
} 

Answer 1

首先，你必须覆盖INFO2的指数？

其次，看到丹尼尔郎咸平的“搜索在RavenDB字符串属性”此处的博客文章：

http://daniellang.net/searching-on-string-properties-in-ravendb/

如果有帮助，这里就是我创建的索引：

public class LogMessageCreatedTime : AbstractIndexCreationTask<LogMessage> 
{ 
    public LogMessageCreatedTime() 
    { 
     Map = messages => from message in messages 
          select new { MessageCreatedTime = message.MessageCreatedTime }; 
    } 
} 

又如何我在运行时添加了它：

private static DocumentStore GetDatabase() 
{    
    DocumentStore documentStore = new DocumentStore();    

    try 
    { 
     documentStore.ConnectionStringName = "RavenDb";     
     documentStore.Initialize(); 

     // Tell Raven to create our indexes. 
     IndexCreation.CreateIndexes(typeof(DataAccessFactory).Assembly, documentStore); 
    } 
    catch 
    { 
     documentStore.Dispose(); 
     throw; 
    } 

    return documentStore; 
} 

就我而言，我不必明确查询索引;当我正常查询时才使用它。

Answer 2

正如Bob所暗示的那样，您应该确保您在Raven中创建了涵盖您打算查询的字段的索引。

乌鸦非常快，可以让你走很长的路，而不需要做太多。 然而，一旦你开始进入大文件号码，或者需要非默认的东西，你会发现你需要静态索引。

在Raven中有很多关于设置和使用索引的示例。