Class Int64Field
Field that indexes System.Int64 values for efficient range filtering and sorting. Here's an example usage:
document.Add(new Int64Field(name, 6L, Field.Store.NO));
For optimal performance, re-use the Int64Field and
Document instance for more than one document:
Int64Field field = new Int64Field(name, 0L, Field.Store.NO);
Document document = new Document();
document.Add(field);
for (all documents) {
...
field.SetInt64Value(value)
writer.AddDocument(document);
...
}
See also Int32Field, SingleField,
DoubleField.
Any type that can be converted to long can also be indexed. For example, date/time values represented by a System.DateTime can be translated into a long value using the System.DateTime.Ticks property. If you don't need millisecond precision, you can quantize the value, either by dividing the result of System.DateTime.Ticks or using the separate getters (for year, month, etc.) to construct an System.Int32 or System.Int64 value.
To perform range querying or filtering against a Int64Field, use NumericRangeQuery<T> or NumericRangeFilter<T>. To sort according to a Int64Field, use the normal numeric sort types, eg INT64. Int64Field values can also be loaded directly from IFieldCache.
You may add the same field name as an Int64Field 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 Int64Field.
An Int64Field 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 LongField in Lucene
@since 2.9Inherited Members
Namespace: Lucene.Net.Documents
Assembly: Lucene.Net.dll
Syntax
public sealed class Int64Field : Field, IIndexableField, IFormattable
Constructors
| Improve this Doc View SourceInt64Field(String, Int64, Field.Store)
Creates a stored or un-stored Int64Field with the provided value
and default precisionStep
PRECISION_STEP_DEFAULT (4).
Declaration
public Int64Field(string name, long value, Field.Store stored)
Parameters
Type | Name | Description |
---|---|---|
System.String | name | field name |
System.Int64 | value | 64-bit System.Int64 value |
Field.Store | stored | YES if the content should also be stored |
Exceptions
Type | Condition |
---|---|
System.ArgumentNullException | if the field |
Int64Field(String, Int64, FieldType)
Expert: allows you to customize the FieldType.
Declaration
public Int64Field(string name, long value, FieldType type)
Parameters
Type | Name | Description |
---|---|---|
System.String | name | field name |
System.Int64 | value | 64-bit System.Int64 value |
FieldType | type | customized field type: must have NumericType of INT64. |
Exceptions
Type | Condition |
---|---|
System.ArgumentNullException | if the field |
System.ArgumentException | if the field type does not have a NumericType of INT64 |
Fields
| Improve this Doc View SourceTYPE_NOT_STORED
Type for a Int64Field that is not stored: normalization factors, frequencies, and positions are omitted.
Declaration
public static readonly FieldType TYPE_NOT_STORED
Field Value
Type | Description |
---|---|
FieldType |
TYPE_STORED
Type for a stored Int64Field: normalization factors, frequencies, and positions are omitted.
Declaration
public static readonly FieldType TYPE_STORED
Field Value
Type | Description |
---|---|
FieldType |