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

Class PushLimitIntoTableSourceScanRule

java.lang.Object
org.apache.calcite.plan.RelOptRule
org.apache.flink.table.planner.plan.rules.logical.PushLimitIntoTableSourceScanRule
public class PushLimitIntoTableSourceScanRule extends org.apache.calcite.plan.RelOptRule
Planner rule that tries to push limit into a FlinkLogicalTableSourceScan, which table is a TableSourceTable. And the table source in the table is a SupportsLimitPushDown. The original limit will still be retained. The reasons why the limit still be retained: 1.If the source is required to return the exact number of limit number, the implementation of the source is highly required. The source is required to accurately control the record number of split, and the parallelism setting also need to be adjusted accordingly. 2.When remove the limit, maybe filter will be pushed down to the source after limit pushed down. The source need know it should do limit first and do the filter later, it is hard to implement. 3.We can support limit with offset, we can push down offset + fetch to table source.

  • Nested Class Summary

    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 PushLimitIntoTableSourceScanRule
    INSTANCE
     

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

    description, operands, relBuilderFactory

  • Constructor Summary

    Constructors
    Constructor
    Description
    PushLimitIntoTableSourceScanRule()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    matches(org.apache.calcite.plan.RelOptRuleCall call)
     
    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, 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

  • Constructor Details

    • PushLimitIntoTableSourceScanRule

      public PushLimitIntoTableSourceScanRule()

  • Method Details

    • matches

      public boolean matches(org.apache.calcite.plan.RelOptRuleCall call)
      Overrides:
      matches in class org.apache.calcite.plan.RelOptRule

    • onMatch

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