What is difference between match and bool must match query in Elasticsearch

问题

What is the difference between Only match and bool must match query in ES?

First, Only use the match query

{
   "query":{
      "match":{
         "address":"mill"
      }
   }
}

Second, use compound query

{
  "query": {
    "bool": {
      "must": [
        { "match": { "address": "mill" } }
      ]
     }
   }
}

Can you tell me everything? What is difference between them?

回答1:

When you use only one match inside a bool must clause then there is no difference, the bool clause is useful when you want to combine multiple(boolean) criteria, more info on official ES doc. It supports below criteria.

must
must_not
filter
should

Let me show by taking a small example from your question.

Index mapping with just address and first_name

{
    "mappings": {
        "properties": {
            "address": {
                "type": "text"
            },
            "first_name" :{
                "type" : "text"
            }
        }
    }
}

Index 3 docs, all having same address `mill`, but different `first_name`

{
   "address" : "mill",
   "first_name" : "Johnson"
}

{
   "address" : "mill",
   "first_name" : "Parker"
}

{
   "address" : "mill",
   "first_name" : "opster"
}

Search query to show all adresses of `mill` but must_not contain first_name as `parker`

{
    "query": {
        "bool": {
            "must": [
                {
                    "match": {
                        "address": "mill"
                    }
                },
                {
                    "must_not": {
                        "first_name": "parker"
                    }
                }
            ]
        }
    }
}

Result only 2 address

"hits": [
         {
            "_index": "so-60620921-bool",
            "_type": "_doc",
            "_id": "2",
            "_score": 0.13353139,
            "_source": {
               "address": "mill",
               "first_name": "opster"
            }
         },
         {
            "_index": "so-60620921-bool",
            "_type": "_doc",
            "_id": "3",
            "_score": 0.13353139,
            "_source": {
               "address": "mill",
               "first_name": "Johnson"
            }
         }
      ]

Based on the OP comments, providing the query and filter context, to understand the performance aspects in details.

回答2:

As written in your question, they will perform the same action.

The match query is a very straight forward full-text condition statement.

The bool query allows you to add multiple fields and multiple conditions such as exists (to validate a certain field is found in the documents), should (an OR equivalent) and must_not (a NOT equivalent).

Taking again your example, since the bool query only has a single must, match condition, it will only return all the documents with the value mill contained in the address field.

Hope this is helpful! :)

来源：https://stackoverflow.com/questions/60646098/what-is-difference-between-match-and-bool-must-match-query-in-elasticsearch

标签

ElasticSearch

elasticsearch-query

booleanquery