Span field masking query
editSpan field masking query
editWrapper 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:
resp = client.search( query={ "span_near": { "clauses": [ { "span_term": { "text": "quick brown" } }, { "span_field_masking": { "query": { "span_term": { "text.stems": "fox" } }, "field": "text" } } ], "slop": 5, "in_order": False } }, highlight={ "require_field_match": False, "fields": { "*": {} } }, ) print(resp)
response = client.search( body: { query: { span_near: { clauses: [ { span_term: { text: 'quick brown' } }, { span_field_masking: { query: { span_term: { 'text.stems' => 'fox' } }, field: 'text' } } ], slop: 5, in_order: false } }, highlight: { require_field_match: false, fields: { "*": {} } } } ) puts response
const response = await client.search({ query: { span_near: { clauses: [ { span_term: { text: "quick brown", }, }, { span_field_masking: { query: { span_term: { "text.stems": "fox", }, }, field: "text", }, }, ], slop: 5, in_order: false, }, }, highlight: { require_field_match: false, fields: { "*": {}, }, }, }); console.log(response);
GET /_search { "query": { "span_near": { "clauses": [ { "span_term": { "text": "quick brown" } }, { "span_field_masking": { "query": { "span_term": { "text.stems": "fox" } }, "field": "text" } } ], "slop": 5, "in_order": false } }, "highlight": { "require_field_match" : false, "fields": { "*": {} } } }
Original field on which we do the search |
|
Masked field, which we are masking with the original field |
|
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.