Class DirectDocValuesFormat

In-memory docvalues format that does no (or very little) compression. Indexed values are stored on disk, but then at search time all values are loaded into memory as simple .NET arrays. For numeric values, it uses byte[], short[], int[], long[] as necessary to fit the range of the values. For binary values, there is an int (4 bytes) overhead per value.

Limitations:

  • For binary and sorted fields the total space required for all binary values cannot exceed about 2.1 GB (see MAX_TOTAL_BYTES_LENGTH).
  • For sorted set fields, the sum of the size of each document's set of values cannot exceed about 2.1 B values (see MAX_SORTED_SET_ORDS). For example, if every document has 10 values (10 instances of Lucene.Net.Documents.SortedSetDocValuesField) added, then no more than ~210 M documents can be added to one segment.
Inheritance
object
DocValuesFormat
DirectDocValuesFormat
Inherited Members
DocValuesFormat.SetDocValuesFormatFactory(IDocValuesFormatFactory)
DocValuesFormat.GetDocValuesFormatFactory()
DocValuesFormat.Name
DocValuesFormat.ToString()
DocValuesFormat.AvailableDocValuesFormats
Namespace: Lucene.Net.Codecs.Memory
Assembly: Lucene.Net.Codecs.dll
Syntax
[DocValuesFormatName("Direct")]
public class DirectDocValuesFormat : DocValuesFormat

Constructors

DirectDocValuesFormat()

Sole constructor.

Declaration
public DirectDocValuesFormat()

Fields

MAX_SORTED_SET_ORDS

The sum of the number of values across all documents in a sorted set field cannot exceed this.

Declaration
public static readonly int MAX_SORTED_SET_ORDS
Field Value
Type Description
int

MAX_TOTAL_BYTES_LENGTH

The sum of all byte lengths for binary field, or for the unique values in sorted or sorted set fields, cannot exceed this.

Declaration
public static readonly int MAX_TOTAL_BYTES_LENGTH
Field Value
Type Description
int

Methods

FieldsConsumer(SegmentWriteState)

Returns a Lucene.Net.Codecs.DocValuesConsumer to write docvalues to the index.

Declaration
public override DocValuesConsumer FieldsConsumer(SegmentWriteState state)
Parameters
Type Name Description
SegmentWriteState state
Returns
Type Description
DocValuesConsumer
Overrides
Lucene.Net.Codecs.DocValuesFormat.FieldsConsumer(Lucene.Net.Index.SegmentWriteState)

FieldsProducer(SegmentReadState)

Returns a Lucene.Net.Codecs.DocValuesProducer to read docvalues from the index.

NOTE: by the time this call returns, it must hold open any files it will need to use; else, those files may be deleted. Additionally, required files may be deleted during the execution of this call before there is a chance to open them. Under these circumstances an IOException should be thrown by the implementation. IOExceptions are expected and will automatically cause a retry of the segment opening logic with the newly revised segments.
Declaration
public override DocValuesProducer FieldsProducer(SegmentReadState state)
Parameters
Type Name Description
SegmentReadState state
Returns
Type Description
DocValuesProducer
Overrides
Lucene.Net.Codecs.DocValuesFormat.FieldsProducer(Lucene.Net.Index.SegmentReadState)