Package org.elasticsearch.xpack.esql.analysis

Class InSubqueryResolver

java.lang.Object

org.elasticsearch.xpack.esql.analysis.InSubqueryResolver

public class InSubqueryResolver
extends Object

Resolves InSubquery expressions in Filter conditions by rewriting them into SemiJoin, AntiJoin, or MarkJoin nodes depending on where the InSubquery sits inside the boolean expression:

• An InSubquery (optionally wrapped in Not) at the top of an AND-conjunct becomes a row-filtering SemiJoin / AntiJoin stacked on top of the remaining filter — the most efficient shape, used for the common conjunctive case.
• An InSubquery that appears as a child of Or (or of Not below an Or) is replaced with a synthetic boolean attribute and a MarkJoin is stacked below the rewritten Filter; the mark attribute carries the three-valued IN result up into normal boolean evaluation.
• An InSubquery wrapped in any other expression (a function argument, an IS NOT NULL, an arithmetic operator, etc.) is left in place; the post-resolution verify(org.elasticsearch.xpack.esql.plan.logical.LogicalPlan) step rejects the query with a VerificationException.

This runs before PreAnalyzer so the subquery plans, originally embedded inside InSubquery expressions, become children of join nodes and visible to standard plan traversals. This eliminates the need for separate InSubquery-aware traversals in PreAnalyzer, FieldNameUtils, and InferenceService.

The join's rightFields are left empty at this stage because the subquery output is not yet resolved. The Analyzer's ResolveRefs fills them in during the Resolution batch.

Constructor Summary

Constructors

Constructor	Description
InSubqueryResolver()

Method Summary

Modifier and Type	Method	Description
static boolean	hasInSubqueryInFilter(LogicalPlan plan)	Returns true if the pre-resolution plan contains any InSubquery expression inside a Filter (i.e.
static LogicalPlan	resolve(LogicalPlan plan)	Resolves all InSubquery expressions in Filter conditions and validates the result.
static LogicalPlan	resolveInSubqueryInFilter(Filter filter)	Make this public, so that ViewResolver can drive IN subquery resolution.
static void	verify(LogicalPlan plan)

Methods inherited from class java.lang.Object

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

Constructor Details

InSubqueryResolver

public InSubqueryResolver()

Method Details

resolve

public static LogicalPlan resolve(LogicalPlan plan)

Resolves all InSubquery expressions in Filter conditions and validates the result. Throws a VerificationException when an InSubquery survived rewriting (e.g. inside an EVAL, SORT, STATS BY clause, or wrapped in a non-boolean expression).

Synchronous — does no I/O. Async callers should invoke this inside an delegateFailureAndWrap lambda so the thrown VerificationException is routed to onFailure.

Telemetry for IN_SUBQUERY is collected separately by the session — see EsqlSession#gatherInSubqueryMetrics, which uses hasInSubqueryInFilter(org.elasticsearch.xpack.esql.plan.logical.LogicalPlan) on the pre-resolution plan because by the time this method returns the originating InSubquery expressions have been replaced with SemiJoin/AntiJoin/MarkJoin and are no longer visible to plan traversals. The WHERE counter still picks up SemiJoin/AntiJoin/MarkJoin in the post-resolution plan walk (see FeatureMetric#WHERE), so the WHERE bit does not need to be set up-front here.

hasInSubqueryInFilter

public static boolean hasInSubqueryInFilter(LogicalPlan plan)

Returns true if the pre-resolution plan contains any InSubquery expression inside a Filter (i.e. as part of a WHERE condition). Used by the session to decide whether to increment the IN_SUBQUERY telemetry counter — once per query, in the same spirit as EsqlSession#gatherViewMetrics.

Restricted to Filter conditions because InSubquery occurrences elsewhere (EVAL, SORT, STATS BY, etc.) are rejected by verify(org.elasticsearch.xpack.esql.plan.logical.LogicalPlan) today.

resolveInSubqueryInFilter

public static LogicalPlan resolveInSubqueryInFilter(Filter filter)

Make this public, so that ViewResolver can drive IN subquery resolution.

verify

public static void verify(LogicalPlan plan)