Storing data in index

After the tokenization and analysis process is complete, the resulting tokens are stored in an index, which is now ready to be search with. Only fields in the final index projection could be used for searches, and the actual tokens stored for each depend on how the selected Analyzer processed the original text.

Lucene allows storing the original token text for fields, and RavenDB exposes this feature in the index definition object via Stores.

By default, tokens are saved to the index as Indexed and Analyzed but not Stored - that is: they can be searched on using a specific Analyzer (or the default one), but their original value is unavailable after indexing. Enabling field storage causes values to be available for retrieval via the ProjectFromIndexFieldsInto, transformers, or other projection functions. It is done like this:

public class Employees_ByFirstAndLastName : AbstractIndexCreationTask<Employee>
{
	public Employees_ByFirstAndLastName()
	{
		Map = employees => from employee in employees
					select new
					{
						employee.FirstName,
						employee.LastName
					};

		Stores.Add(x => x.FirstName, FieldStorage.Yes);
		Stores.Add(x => x.LastName, FieldStorage.Yes);
	}
}

store
	.DatabaseCommands
	.PutIndex(
		"Employees_ByFirstAndLastName",
		new IndexDefinition
		{
			Map = @"from employee in docs.Employees
					select new
					{
						employee.FirstName,
						employee.LastName
					}",
			Stores = new Dictionary<string, FieldStorage>
			{
				{ "FirstName", FieldStorage.Yes }, 
				{ "LastName", FieldStorage.Yes }
			}
		});

Remarks