Class Int32Field

Field that indexes System.Int32 values for efficient range filtering and sorting. Here's an example usage: 

    document.Add(new Int32Field(name, 6, Field.Store.NO));
For optimal performance, re-use the Int32Field and Document instance for more than one document: 
    Int32Field field = new Int32Field(name, 6, Field.Store.NO);
    Document document = new Document();
    document.Add(field);

    for (all documents) 
    {
        ...
        field.SetInt32Value(value)
        writer.AddDocument(document);
        ...
    }
See also Int64Field, SingleField, DoubleField.

To perform range querying or filtering against a Int32Field, use NumericRangeQuery<T> or NumericRangeFilter<T>. To sort according to a Int32Field, use the normal numeric sort types, eg INT32. Int32Field values can also be loaded directly from IFieldCache.

You may add the same field name as an Int32Field to the same document more than once. Range querying and filtering will be the logical OR of all values; so a range query will hit all documents that have at least one value in the range. However sort behavior is not defined. If you need to sort, you should separately index a single-valued Int32Field.

An Int32Field will consume somewhat more disk space in the index than an ordinary single-valued field. However, for a typical index that includes substantial textual content per document, this increase will likely be in the noise.

Within Lucene, each numeric value is indexed as a trie structure, where each term is logically assigned to larger and larger pre-defined brackets (which are simply lower-precision representations of the value). The step size between each successive bracket is called the precisionStep, measured in bits. Smaller precisionStep values result in larger number of brackets, which consumes more disk space in the index but may result in faster range search performance. The default value, 4, was selected for a reasonable tradeoff of disk space consumption versus performance. You can create a custom FieldType and invoke the NumericPrecisionStep setter if you'd like to change the value. Note that you must also specify a congruent value when creating NumericRangeQuery<T> or NumericRangeFilter<T>. For low cardinality fields larger precision steps are good. If the cardinality is < 100, it is fair to use System.Int32.MaxValue, which produces one term per value.

For more information on the internals of numeric trie indexing, including the PrecisionStep precisionStep configuration, see NumericRangeQuery<T>. The format of indexed values is described in NumericUtils.

If you only need to sort by numeric value, and never run range querying/filtering, you can index using a precisionStep of System.Int32.MaxValue. this will minimize disk space consumed.

More advanced users can instead use NumericTokenStream directly, when indexing numbers. this class is a wrapper around this token stream type for easier, more intuitive usage.

NOTE: This was IntField in Lucene

@since 2.9

Inheritance
System.Object
Field
Int32Field
Implements
Inherited Members
System.Object.Equals(System.Object)
System.Object.Equals(System.Object, System.Object)
System.Object.GetHashCode()
System.Object.GetType()
System.Object.MemberwiseClone()
System.Object.ReferenceEquals(System.Object, System.Object)
Namespace: Lucene.Net.Documents
Assembly: Lucene.Net.dll
Syntax
public sealed class Int32Field : Field, IIndexableField

Constructors

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Int32Field(String, Int32, Field.Store)

Creates a stored or un-stored Int32Field with the provided value and default precisionStep PRECISION_STEP_DEFAULT (4).

Declaration
public Int32Field(string name, int value, Field.Store stored)
Parameters
Type Name Description
System.String name

field name

System.Int32 value

32-bit System.Int32 value

Field.Store stored

YES if the content should also be stored

Exceptions
Type Condition
System.ArgumentNullException

if the field name is null.

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Int32Field(String, Int32, FieldType)

Expert: allows you to customize the FieldType.

Declaration
public Int32Field(string name, int value, FieldType type)
Parameters
Type Name Description
System.String name

field name

System.Int32 value

32-bit System.Int32 value

FieldType type

customized field type: must have NumericType of INT32.

Exceptions
Type Condition
System.ArgumentNullException

if the field name or type is NONE

System.ArgumentException

if the field type does not have a NumericType of INT32

Fields

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TYPE_NOT_STORED

Type for an Int32Field that is not stored: normalization factors, frequencies, and positions are omitted.

Declaration
public static readonly FieldType TYPE_NOT_STORED
Field Value
Type Description
FieldType
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TYPE_STORED

Type for a stored Int32Field: normalization factors, frequencies, and positions are omitted.

Declaration
public static readonly FieldType TYPE_STORED
Field Value
Type Description
FieldType

Implements

Extension Methods