Package org.elasticsearch.xpack.esql.approximation

Class ApproximationVerifier

java.lang.Object

org.elasticsearch.xpack.esql.approximation.ApproximationVerifier

public class ApproximationVerifier
extends Object

This class approximate results for certain classes of ES|QL queries. Approximate results are usually much faster to compute than exact results.

A query is currently suitable for approximation if:

• it has a supported STATS layout: without FORK, exactly one STATS; with FORK, either FROM | FORK (...) | STATS (one STATS after the fork, none inside branches) or FROM | STATS | FORK (...) (exactly one STATS per branch)
• the other processing commands are from the supported set (SUPPORTED_COMMANDS)
• the aggregate functions are from the supported set (SUPPORTED_SINGLE_VALUED_AGGS and SUPPORTED_MULTIVALUED_AGGS)

Some of these restrictions may be lifted in the future.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final record	ApproximationVerifier.QueryProperties

Constructor Summary

Constructors

Constructor	Description
ApproximationVerifier()

Method Summary

Modifier and Type	Method	Description
static ApproximationVerifier.QueryProperties	verifyPlan(LogicalPlan logicalPlan, TransportVersion minimumVersion)	Verifies that a plan is suitable for approximation.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ApproximationVerifier

public ApproximationVerifier()

Method Details

verifyPlan

public static ApproximationVerifier.QueryProperties verifyPlan(LogicalPlan logicalPlan,
 TransportVersion minimumVersion)

Verifies that a plan is suitable for approximation.

Returns:

the query properties relevant for approximation if it's suitable, or null otherwise Adds warning headers as a side effect when the plan is not suitable