Query DSLedit

Elasticsearch provides a full Query DSL (Domain Specific Language) based on JSON to define queries. Think of the Query DSL as an AST (Abstract Syntax Tree) of queries, consisting of two types of clauses:

Leaf query clauses
Leaf query clauses look for a particular value in a particular field, such as the match, term or range queries. These queries can be used by themselves.
Compound query clauses
Compound query clauses wrap other leaf or compound queries and are used to combine multiple queries in a logical fashion (such as the bool or dis_max query), or to alter their behaviour (such as the constant_score query).

Query clauses behave differently depending on whether they are used in query context or filter context.

Allow expensive queries

Certain types of queries will generally execute slowly due to the way they are implemented, which can affect the stability of the cluster. Those queries can be categorised as follows:

The execution of such queries can be prevented by setting the value of the search.allow_expensive_queries setting to false (defaults to true).