Dis max query in Elasticsearch - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the score behavior of this dis_max query?

Given the following Elasticsearch dis_max query, what will be the _score of a document that matches both clauses equally with a tie_breaker of 0.3?

Elasticsearch

{
  "query": {
    "dis_max": {
      "tie_breaker": 0.3,
      "queries": [
        { "match": { "title": "apple" } },
        { "match": { "description": "apple" } }
      ]
    }
  }
}

A The score is the sum of both match scores without any multiplier.

B The score is the average of the two match scores.

C The score is the maximum score of the two matches plus 0.3 times the other score.

D The score is only the maximum score of the two matches, ignoring the tie_breaker.

💡 Hint

Remember that dis_max uses the highest score plus a fraction of the others based on tie_breaker.

The dis_max query returns the maximum score from its subqueries plus a fraction (tie_breaker) of the other scores. This helps boost documents matching multiple queries without simply summing all scores.

🧠 Conceptual

intermediate

Which use case best fits a dis_max query?

Which scenario is the best reason to use a dis_max query in Elasticsearch?

A You want to find documents matching any of several queries but prefer the highest scoring match with some bonus for others.

B You want to boost documents that match all queries by multiplying their scores.

C You want to filter documents strictly matching all queries.

D You want to combine multiple queries and sum all their scores equally.

💡 Hint

Dis max is about picking the best match with some influence from others.

Dis max is designed to pick the highest scoring query match and add a fraction of other matches, useful when you want to prefer the best match but still reward multiple matches.

🔧 Debug

advanced

Why does this dis_max query ignore the tie_breaker?

Consider this dis_max query: { "query": { "dis_max": { "tie_breaker": 0.5, "queries": [ { "match": { "field1": "test" } }, { "match": { "field2": "test" } } ] } } } Why might the tie_breaker have no effect on the scoring?

A Because only one of the queries matches the document, so no tie breaker is applied.

B Because the tie_breaker value must be between 0 and 1 exclusive, and 0.5 is invalid.

C Because dis_max requires a minimum_should_match parameter to apply tie_breaker.

D Because the queries are inside a bool filter, which disables scoring.

💡 Hint

Tie breaker only affects when multiple queries match.

The tie_breaker only adds a fraction of the scores from other matching queries. If only one query matches, the tie_breaker has no effect.

📝 Syntax

advanced

Identify the syntax error in this dis_max query

Which option contains a syntax error in the dis_max query?

Elasticsearch

{
  "query": {
    "dis_max": {
      "tie_breaker": 0.2,
      "queries": [
        { "match": { "field": "value1" } },
        { "match": { "field": "value2" } }
      ]
    }
  }
}

A { "dis_max": { "tieBreaker": 0.2, "queries": [ { "match": { "field": "value1" } }, { "match": { "field": "value2" } } ] } }

B { "dis_max": { "tie_breaker": 0.2, "query": [ { "match": { "field": "value1" } }, { "match": { "field": "value2" } } ] } }

C { "dis_max": { "tie_breaker": 0.2, "queries": [ { "match": { "field": "value1" } }, { "match": { "field": "value2" } } ] } }

D } } ] } } "2eulav" :"dleif" { :"hctam" { ,} } "1eulav" :"dleif" { :"hctam" { [ :"seireuq" ,2.0 :"rekaerb_eit" { :"xam_sid" {

💡 Hint

Check the key name for the list of queries inside dis_max.

The correct key for the list of queries inside dis_max is "queries" not "query". Using "query" causes a syntax error.

🚀 Application

expert

How to combine dis_max with boosting for best relevance?

You want to search documents matching either 'title' or 'content' fields. You want the best match to score highest but also boost matches in 'title' by 2x. Which query achieves this?

A

{
  "dis_max": {
    "tie_breaker": 0.1,
    "queries": [
      { "match": { "title": "search" } },
      { "match": { "content": { "query": "search", "boost": 2 } } }
    ]
  }
}

B

{
  "bool": {
    "should": [
      { "match": { "title": { "query": "search", "boost": 2 } } },
      { "match": { "content": "search" } }
    ]
  }
}

C

{
  "function_score": {
    "query": {
      "dis_max": {
        "tie_breaker": 0.1,
        "queries": [
          { "match": { "title": "search" } },
          { "match": { "content": "search" } }
        ]
      }
    },
    "boost": 2
  }
}

D

{
  "dis_max": {
    "tie_breaker": 0.1,
    "queries": [
      { "match": { "title": { "query": "search", "boost": 2 } } },
      { "match": { "content": "search" } }
    ]
  }
}

💡 Hint

Boost inside the match query affects that field's score before dis_max combines them.

Boosting the 'title' match inside the dis_max queries increases its score before dis_max picks the max plus tie breaker. This way, matches in 'title' get higher priority.