Package org.apache.flink.table.planner.plan.rules.logical

Class WrapJsonAggFunctionArgumentsRule

java.lang.Object

org.apache.calcite.plan.RelOptRule

org.apache.calcite.plan.RelRule<WrapJsonAggFunctionArgumentsRule.Config>

org.apache.flink.table.planner.plan.rules.logical.WrapJsonAggFunctionArgumentsRule

@Internal
@Enclosing
public class WrapJsonAggFunctionArgumentsRule
extends org.apache.calcite.plan.RelRule<WrapJsonAggFunctionArgumentsRule.Config>

Transforms JSON aggregation functions by wrapping operands into BuiltInFunctionDefinitions.JSON_STRING.

Essentially, a call like JSON_OBJECTAGG(f0 VALUE f1) will be transformed into JSON_OBJECTAGG(f0 VALUE JSON_STRING(f1)). By placing a marker RelHint on the aggregation afterwards we ensure that this transformation occurs just once.

BuiltInFunctionDefinitions.JSON_STRING will take care of serializing the values into their correct representation, and the actual aggregation function's implementation can simply insert the values as raw nodes instead. This avoids having to re-implement the logic for all supported types in the aggregation function again.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	WrapJsonAggFunctionArgumentsRule.Config	Configuration for WrapJsonAggFunctionArgumentsRule.

Nested classes/interfaces inherited from class org.apache.calcite.plan.RelRule

org.apache.calcite.plan.RelRule.Done, org.apache.calcite.plan.RelRule.MatchHandler<R extends org.apache.calcite.plan.RelOptRule>, org.apache.calcite.plan.RelRule.OperandBuilder, org.apache.calcite.plan.RelRule.OperandDetailBuilder<R extends org.apache.calcite.rel.RelNode>, org.apache.calcite.plan.RelRule.OperandTransform

Nested classes/interfaces inherited from class org.apache.calcite.plan.RelOptRule

org.apache.calcite.plan.RelOptRule.ConverterRelOptRuleOperand

Field Summary

Fields

Modifier and Type	Field	Description
static org.apache.calcite.plan.RelOptRule	INSTANCE

Fields inherited from class org.apache.calcite.plan.RelRule

config

Fields inherited from class org.apache.calcite.plan.RelOptRule

description, operands, relBuilderFactory

Constructor Summary

Constructors

Constructor	Description
WrapJsonAggFunctionArgumentsRule(WrapJsonAggFunctionArgumentsRule.Config config)

Method Summary

Modifier and Type	Method	Description
void	onMatch(org.apache.calcite.plan.RelOptRuleCall call)

Methods inherited from class org.apache.calcite.plan.RelOptRule

any, convert, convert, convertList, convertOperand, convertOperand, equals, equals, getOperand, getOperands, getOutConvention, getOutTrait, hashCode, matches, none, operand, operand, operand, operand, operand, operandJ, operandJ, some, toString, unordered

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

INSTANCE

public static final org.apache.calcite.plan.RelOptRule INSTANCE

Constructor Detail

WrapJsonAggFunctionArgumentsRule

public WrapJsonAggFunctionArgumentsRule(WrapJsonAggFunctionArgumentsRule.Config config)

Method Detail

onMatch

public void onMatch(org.apache.calcite.plan.RelOptRuleCall call)

Specified by:

onMatch in class org.apache.calcite.plan.RelOptRule