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 final 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 Details

    • INSTANCE

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

  • Constructor Details

  • Method Details

    • onMatch

      public void onMatch(org.apache.calcite.plan.RelOptRuleCall call)
      Specified by:
      onMatch in class org.apache.calcite.plan.RelOptRule