mirror of
https://github.com/elastic/elasticsearch.git
synced 2025-04-24 23:27:25 -04:00
d6c53e03d2
Improvement includes: 1. Remove reference to Lucene queries (this information is not necessary for Elastic users, and can be outdated) 2. For `span_field_masking` include a node to use "require_field_match" : false parameter for highlighters to work. Closes #101804
60 lines
1.8 KiB
Text
60 lines
1.8 KiB
Text
[[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.
|
|
|
|
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,console]
|
|
--------------------------------------------------
|
|
GET /_search
|
|
{
|
|
"query": {
|
|
"span_near": {
|
|
"clauses": [
|
|
{
|
|
"span_term": {
|
|
"text": "quick brown"
|
|
}
|
|
},
|
|
{
|
|
"span_field_masking": {
|
|
"query": {
|
|
"span_term": {
|
|
"text.stems": "fox" <1>
|
|
}
|
|
},
|
|
"field": "text" <2>
|
|
}
|
|
}
|
|
],
|
|
"slop": 5,
|
|
"in_order": false
|
|
}
|
|
},
|
|
"highlight": {
|
|
"require_field_match" : false, <3>
|
|
"fields": {
|
|
"*": {}
|
|
}
|
|
}
|
|
}
|
|
--------------------------------------------------
|
|
<1> Original field on which we do the search
|
|
<2> Masked field, which we are masking with the original field
|
|
<3> Use "require_field_match" : false to highlight the masked field
|
|
|
|
Note: `span_field_masking` query may have unexpected scoring and highlighting
|
|
behaviour. This is because the query returns and highlights the masked field,
|
|
but scoring and highlighting are done using the terms statistics and offsets
|
|
of the original field.
|
|
|
|
Note: For highlighting to work the parameter: `require_field_match` should
|
|
be set to `false` on the highlighter.
|