Boosting results based on selected types in elasticsearch - elasticsearch

Question

I have different types indexed in elastic search.
but, if I want to boost my results on some selected types then what should I do?
I could use type filter in boosting query, but type filter allows me only one type to be used in filter. I need results to be boosted on the basis of multiple types.
Example:
I have Person, Event, Location data indexed in elastic search where Person, Location and Event are my types.
I am searching for keyword 'London' in all types but i want Person and Event type records to be boosted than Location.
How could I achieve the same?

Answer 1

One of the ways of getting the desired functionality is by wrapping your query inside a bool query and then make use of the should clause, in order to boost certain documents
Small example:
POST test/person
{
"title": "london elise moore"
}
POST test/event
{
"title" : "london is a great city"
}
Without boost:
GET test/_search
{
"query": {
"bool": {
"must": [
{
"match": {
"title": "london"
}
}
]
}
}
}
With the following response:
"hits": {
"total": 2,
"max_score": 0.2972674,
"hits": [
{
"_index": "test",
"_type": "person",
"_id": "AVVx621GYvUb9aQn6r5X",
"_score": 0.2972674,
"_source": {
"title": "london elise moore"
}
},
{
"_index": "test",
"_type": "event",
"_id": "AVVx63LrYvUb9aQn6r5Y",
"_score": 0.26010898,
"_source": {
"title": "london is a great city"
}
}
]
}
And now with the added should clause:
GET test/_search
{
"query": {
"bool": {
"must": [
{
"match": {
"title": "london"
}
}
],
"should": [
{
"term": {
"_type": {
"value": "event",
"boost": 2
}
}
}
]
}
}
}
Which gives back the following response:
"hits": {
"total": 2,
"max_score": 1.0326607,
"hits": [
{
"_index": "test",
"_type": "event",
"_id": "AVVx63LrYvUb9aQn6r5Y",
"_score": 1.0326607,
"_source": {
"title": "london is a great city"
}
},
{
"_index": "test",
"_type": "person",
"_id": "AVVx621GYvUb9aQn6r5X",
"_score": 0.04235228,
"_source": {
"title": "london elise moore"
}
}
]
}
You could even leave out the extra boost in the should clause, cause if the should clause matches it will boost the result :)
Hope this helps!

Answer 2

I see two ways of doing that using that but both is using scripts
1. using sorting
POST c1_1/_search
{
"from": 0,
"size": 10,
"sort": [
{
"_script": {
"order": "desc",
"type": "number",
"script": "double boost = 1; if(doc['_type'].value == 'Person') { boost *= 2 }; if(doc['_type'].value == 'Event') { boost *= 3}; return _score * boost; ",
"params": {}
}
},
{
"_score": {}
}
],
"query": {
"bool": {
"should": [
{
"query_string": {
"query": "*",
"default_operator": "and"
}
}
],
"minimum_should_match": "1"
}
}
}
Second option Using function score.
POST c1_1/_search
{
"from": 0,
"size": 10,
"query": {
"function_score": {
"query": {
"bool": {
"should": [
{
"query_string": {
"query": "*",
"default_operator": "and"
}
}
],
"minimum_should_match": "1"
}
},
"script_score": {
"script": "_score * (doc['_type'].value == 'Person' || doc['_type'].value == 'Event'? 2 : 1)"
}
}
}
}