CODEWITHSUNDEEP
c#.netravendb
user1765862
user1765862

Reputation: 14205

retrieving data using stream api

I'm using the RavenDB streaming API to retrieve all 355,000 DocsToProcess from my database instance using the following code:

_myDocs = new List<DocsToProcess>();
var query = RavenSession.Query<DocsToProcess>();
using (var enumerator = RavenSession.Advanced.Stream(query))
{
    while (enumerator.MoveNext())
    {
        DocsToProcess u = enumerator.Current.Document;
        _myDocs.Add(u);
     }                
}

However, the following exception message is thrown:

StreamQuery does not support querying dynamic indexes. It is designed to be used with large data-sets and is unlikely to return all data-set after 15 sec of indexing, like Query() does.

How I can correctly iterate through all elements of type DocsToProcess in my C# application?

Upvotes: 0

Views: 950

Answers (3)

Pat Hermens
Pat Hermens

Reputation: 904

Similar to JHo above, the solution that I came up with means that you do not need to make a static index for streaming, because you're relying on the default index and using the StartsWith overload of Stream<T> in the Raven client.

We've found the solution below to work fine for most of our use-cases where we need to get everything from a Raven instance.

public IEnumerable<T> GetAll()
{
    var results = new List<T>();

    var conventions = _documentStore.Conventions ?? new DocumentConvention();
    var defaultIndexStartsWith = conventions.GetTypeTagName(typeof(T));

    using(var session = _documentStore.OpenSession())
    {
        using(var enumerator = session.Advanced.Stream<T>(defaultIndexStartsWith))
        {
            while(enumerator.MoveNext())
                results.Add(enumerator.Current.Document);
        }
    }

    return results;
}

Upvotes: 1

JHo
JHo

Reputation: 466

To get by without creating a static index, you can provide some minimal bounding like this:

    using (var session = store.OpenSession())
    {
        IEnumerator<StreamResult<Employee>> stream =
            session.Advanced.Stream<Employee>("employees/");
        while (stream.MoveNext())
        {
            // ....
        }
    }

Upvotes: 0

Thomas Freudenberg
Thomas Freudenberg

Reputation: 5078

The documentation says explicitly for unbound results:

Important side notes:

  • the index already exists. Creation of a index won't occur and the query error with an IndexDoesNotExistsException exception.

And that's what your exception is saying. You have to create a static index for streaming results.

Upvotes: 3

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