Package org.elasticsearch.xpack.esql.optimizer.rules.logical

Class PruneEmptyForkBranches

java.lang.Object

org.elasticsearch.xpack.esql.rule.Rule<Fork,LogicalPlan>

org.elasticsearch.xpack.esql.optimizer.rules.logical.OptimizerRules.OptimizerRule<Fork>

org.elasticsearch.xpack.esql.optimizer.rules.logical.PruneEmptyForkBranches

public class PruneEmptyForkBranches
extends OptimizerRules.OptimizerRule<Fork>

Removes FORK branches or subqueries from UnionAll that only contain an empty LocalRelation. The simplest case where this can happen is when a FORK branch contains WHERE false. In practice, empty FORK branches can also happen when FORK is used for conditional execution of the query based on query parameters:

FROM my-index METADATA _score
| ...
| FORK ( SORT _score | LIMIT 10) // return top hits every time
       ( WHERE ?include_completion | STATS s = values(title) | COMPLETION ...)

Field Summary

Fields inherited from class org.elasticsearch.xpack.esql.rule.Rule

log

Constructor Summary

Constructors

Constructor	Description
PruneEmptyForkBranches()

Method Summary

Modifier and Type	Method	Description
protected LogicalPlan	rule(Fork fork)

Methods inherited from class org.elasticsearch.xpack.esql.optimizer.rules.logical.OptimizerRules.OptimizerRule

apply

Methods inherited from class org.elasticsearch.xpack.esql.rule.Rule

name, toString, typeToken

Methods inherited from class java.lang.Object

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

Constructor Details

PruneEmptyForkBranches

public PruneEmptyForkBranches()

Method Details

rule

protected LogicalPlan rule(Fork fork)

Specified by:

rule in class OptimizerRules.OptimizerRule<Fork>