RavenDb 对查询数百万文档的性能的期望

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，我发现性能不是我所期望的，如果可能的话几乎是瞬时的，而是在一台相当强大的机器上超过 18 秒。

下面，你会发现我的天真代码。

注意:我现在已经解决了这个问题，最终代码在帖子底部。需要注意的是，您需要索引，它们必须是正确的类型，并且需要让 RavenDB 意识到它们。对通过查询引擎返回的记录的性能和质量非常满意。

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

我添加了这个类

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);
    }
}

并将调用方法更改为如下所示。

        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 秒进行搜索。我错过了什么？另一方面，C:\temp\ravendata\Indexes\InfoIndex%2fSearch 文件夹中有不少新文件，虽然没有我插入数据时多，但运行此代码后它们似乎几乎消失了几次尝试查询。应该 IndexCreation.CreateIndexes(Assembly.GetExecutingAssembly(), store);在插入之前调用，然后才调用？

编辑1

使用此代码，我几乎可以在一个实例中进行查询，但似乎您只能运行一次，所以这就引出了一个问题。它在哪里运行，正确的初始化程序是什么？

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，您是否有涵盖 INFO2 的索引？

其次，请参阅 Daniel Lang 的“在 RavenDB 中搜索字符串属性”博客文章:

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

如果有帮助，以下是我创建索引的方法:

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

以及我如何在运行时添加它:

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，我不必显式查询索引；只是正常查询的时候用的。