46 lines
1.5 KiB
Plaintext
46 lines
1.5 KiB
Plaintext
[[query-dsl-span-field-masking-query]]
|
|
=== Span field masking query
|
|
++++
|
|
<titleabbrev>Span field masking</titleabbrev>
|
|
++++
|
|
|
|
Wrapper to allow span queries to participate in composite single-field span queries by 'lying' about their search field. The span field masking query maps to Lucene's `SpanFieldMaskingQuery`
|
|
|
|
This can be used to support queries like `span-near` or `span-or` across different fields, which is not ordinarily permitted.
|
|
|
|
Span field masking query is invaluable in conjunction with *multi-fields* when same content is indexed with multiple analyzers. For instance we could index a field with the standard analyzer which breaks text up into words, and again with the english analyzer which stems words into their root form.
|
|
|
|
Example:
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
GET /_search
|
|
{
|
|
"query": {
|
|
"span_near": {
|
|
"clauses": [
|
|
{
|
|
"span_term": {
|
|
"text": "quick brown"
|
|
}
|
|
},
|
|
{
|
|
"field_masking_span": {
|
|
"query": {
|
|
"span_term": {
|
|
"text.stems": "fox"
|
|
}
|
|
},
|
|
"field": "text"
|
|
}
|
|
}
|
|
],
|
|
"slop": 5,
|
|
"in_order": false
|
|
}
|
|
}
|
|
}
|
|
--------------------------------------------------
|
|
// CONSOLE
|
|
|
|
Note: as span field masking query returns the masked field, scoring will be done using the norms of the field name supplied. This may lead to unexpected scoring behaviour. |