Does Elasticsearch provide highlighting on "copy_to" field in their newer versions? - elasticsearch

Question

I had used Elasticsearch few years ago(version 6.4.0) and they had no provision to provide highlight the "copy_to" field. I would like to know if they have this provision now?

Answer 1

Yes, highlight can enabled on copy_to field in latest version.
Please check below example which i have tried.
Index Mapping:
PUT my-index-000001
{
"mappings": {
"properties": {
"first_name": {
"type": "text",
"copy_to": "full_name"
},
"last_name": {
"type": "text",
"copy_to": "full_name"
},
"full_name": {
"type": "text"
}
}
}
}
Document Index:
PUT my-index-000001/_doc/1
{
"first_name": "John",
"last_name": "Smith"
}
Query:
GET my-index-000001/_search
{
"query": {
"match": {
"full_name": {
"query": "John Smith",
"operator": "and"
}
}
},
"highlight": {
"fields": {
"full_name": {}
}
}
}
Result:
"hits" : [
{
"_index" : "my-index-000001",
"_type" : "_doc",
"_id" : "1",
"_score" : 0.5753642,
"_source" : {
"first_name" : "John",
"last_name" : "Smith"
},
"highlight" : {
"full_name" : [
"<em>Smith</em>",
"<em>John</em>"
]
}
}
]
Update 1: Search using copy_to field and highlight match to particular field
In below example, search will be happen on full_name field which is copy field and highlight will be happen on first_name field.
Query:
GET my-index-000001/_search
{
"query": {
"match": {
"full_name": {
"query": "John Smith",
"operator": "and"
}
}
},
"highlight": {
"require_field_match": "false",
"fields": {
"first_name": {}
}
}
}
Result:
{
"_index" : "my-index-000001",
"_type" : "_doc",
"_id" : "1",
"_score" : 0.5753642,
"_source" : {
"first_name" : "John",
"last_name" : "Smith"
},
"highlight" : {
"first_name" : [
"<em>John</em>"
]
}
}