Class MatchConfig

java.lang.Object
org.elasticsearch.xpack.esql.enrich.MatchConfig
All Implemented Interfaces:
Writeable

public final class MatchConfig extends Object implements Writeable
Configuration for a field used in the join condition of a LOOKUP JOIN or ENRICH operation.

This class specifies how to match a field from the input data (the "left" side of the join) with a field in the lookup index (the "right" side). The interpretation of its properties depends on the type of join.

For simple field-based joins (e.g., ... ON field1, field2), this configuration represents the right-side field (right.field). In this case, fieldName is the name of the field in the lookup index used to build the query.

For expression-based joins (e.g., ... ON left_field > right_field), this configuration represents the left-side field (left_field). In this case, fieldName is the name of the field whose value is sent to the lookup node.

The channel identifies the position of this field's values within the internal page sent to the lookup node.