Lucene.Net.Search.Function.OrdFieldSource Class Reference

Expert: obtains the ordinal of the field value from the default Lucene Fieldcache using getStringIndex(). The native lucene index order is used to assign an ordinal value for each field value. Field values (terms) are lexicographically ordered by unicode value, and numbered starting at 1. Example:
If there were only three field values: "apple","banana","pear"
then ord("apple")=1, ord("banana")=2, ord("pear")=3 WARNING: ord() depends on the position in an index and can thus change when other documents are inserted or deleted, or if a MultiSearcher is used. More...

Inherits Lucene.Net.Search.Function.ValueSource.

Public Member Functions
	OrdFieldSource (System.String field)
	Constructor for a certain field.
override System.String	Description ()
	description of field, used in explain()
override DocValues	GetValues (IndexReader reader)
	Return the DocValues used by the function query.
override bool	Equals (System.Object o)
	Needed for possible caching of query results - used by ValueSourceQuery.Equals(Object).
override int	GetHashCode ()
	Needed for possible caching of query results - used by ValueSourceQuery.GetHashCode().
Public Member Functions inherited from Lucene.Net.Search.Function.ValueSource
override System.String	ToString ()

Detailed Description

Expert: obtains the ordinal of the field value from the default Lucene Fieldcache using getStringIndex().

The native lucene index order is used to assign an ordinal value for each field value.

Field values (terms) are lexicographically ordered by unicode value, and numbered starting at 1.

Example:
If there were only three field values: "apple","banana","pear"
then ord("apple")=1, ord("banana")=2, ord("pear")=3

WARNING: ord() depends on the position in an index and can thus change when other documents are inserted or deleted, or if a MultiSearcher is used.

<font color="#FF0000"> WARNING: The status of the Search.Function package is experimental. The APIs introduced here might change in the future and will not be supported anymore in such a case.</font>

NOTE: with the switch in 2.9 to segment-based searching, if GetValues is invoked with a composite (multi-segment) reader, this can easily cause double RAM usage for the values in the FieldCache. It's best to switch your application to pass only atomic (single segment) readers to this API.

Definition at line 56 of file OrdFieldSource.cs.

Constructor & Destructor Documentation

Lucene.Net.Search.Function.OrdFieldSource.OrdFieldSource

(

System.String

field

)

Constructor for a certain field.

Parameters

field

field whose values order is used.

Definition at line 107 of file OrdFieldSource.cs.

Member Function Documentation

override System.String Lucene.Net.Search.Function.OrdFieldSource.Description ( )

virtual

description of field, used in explain()

Implements Lucene.Net.Search.Function.ValueSource.

Definition at line 113 of file OrdFieldSource.cs.

override bool Lucene.Net.Search.Function.OrdFieldSource.Equals ( System.Object  o )

virtual

Needed for possible caching of query results - used by ValueSourceQuery.Equals(Object).

See Also

Object.Equals(Object)

Implements Lucene.Net.Search.Function.ValueSource.

Definition at line 126 of file OrdFieldSource.cs.

override int Lucene.Net.Search.Function.OrdFieldSource.GetHashCode ( )

virtual

Needed for possible caching of query results - used by ValueSourceQuery.GetHashCode().

See Also

Object.GetHashCode()

Implements Lucene.Net.Search.Function.ValueSource.

Definition at line 137 of file OrdFieldSource.cs.

override DocValues Lucene.Net.Search.Function.OrdFieldSource.GetValues ( IndexReader  reader )

virtual

Return the DocValues used by the function query.

Parameters

reader

the IndexReader used to read these values. If any caching is involved, that caching would also be IndexReader based.

<throws> IOException for any error. </throws>

Implements Lucene.Net.Search.Function.ValueSource.

Definition at line 119 of file OrdFieldSource.cs.

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The documentation for this class was generated from the following file:

• core/Search/Function/OrdFieldSource.cs