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

Class PushWatermarkIntoTableSourceScanRuleBase

java.lang.Object

org.apache.calcite.plan.RelOptRule

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

Direct Known Subclasses:

PushWatermarkIntoTableSourceScanAcrossCalcRule, PushWatermarkIntoTableSourceScanRule

public abstract class PushWatermarkIntoTableSourceScanRuleBase
extends org.apache.calcite.plan.RelOptRule

Base rule for interface SupportsWatermarkPushDown and SupportsSourceWatermark. It offers a util to push the FlinkLogicalWatermarkAssigner into the FlinkLogicalTableSourceScan.

Nested Class Summary

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

org.apache.calcite.plan.RelOptRule.ConverterRelOptRuleOperand

Field Summary

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

description, operands, relBuilderFactory

Constructor Summary

Constructors

Constructor and Description
PushWatermarkIntoTableSourceScanRuleBase(org.apache.calcite.plan.RelOptRuleOperand operand, String description)

Method Summary

Modifier and Type	Method and Description
protected org.apache.flink.table.planner.plan.nodes.logical.FlinkLogicalTableSourceScan	getNewScan(org.apache.flink.table.planner.plan.nodes.logical.FlinkLogicalWatermarkAssigner watermarkAssigner, org.apache.calcite.rex.RexNode watermarkExpr, org.apache.flink.table.planner.plan.nodes.logical.FlinkLogicalTableSourceScan scan, TableConfig tableConfig, boolean useWatermarkAssignerRowType) It uses the input watermark expression to generate the WatermarkGeneratorSupplier.
protected boolean	supportsWatermarkPushDown(org.apache.flink.table.planner.plan.nodes.logical.FlinkLogicalTableSourceScan scan)

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

any, convert, convert, convertList, convertOperand, convertOperand, equals, equals, getOperand, getOperands, getOutConvention, getOutTrait, hashCode, matches, none, onMatch, 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

Constructor Detail

PushWatermarkIntoTableSourceScanRuleBase

public PushWatermarkIntoTableSourceScanRuleBase(org.apache.calcite.plan.RelOptRuleOperand operand,
                                                String description)

Method Detail

getNewScan

protected org.apache.flink.table.planner.plan.nodes.logical.FlinkLogicalTableSourceScan getNewScan(org.apache.flink.table.planner.plan.nodes.logical.FlinkLogicalWatermarkAssigner watermarkAssigner,
                                                                                                   org.apache.calcite.rex.RexNode watermarkExpr,
                                                                                                   org.apache.flink.table.planner.plan.nodes.logical.FlinkLogicalTableSourceScan scan,
                                                                                                   TableConfig tableConfig,
                                                                                                   boolean useWatermarkAssignerRowType)

It uses the input watermark expression to generate the WatermarkGeneratorSupplier. After the WatermarkStrategy is pushed into the scan, it will build a new scan. However, when FlinkLogicalWatermarkAssigner is the parent of the FlinkLogicalTableSourceScan it should modify the rowtime type to keep the type of plan is consistent. In other cases, it just keep the data type of the scan as same as before and leave the work when rewriting the projection.

NOTES: the row type of the scan is not always as same as the watermark assigner. Because the scan will not add the rowtime column into the row when pushing the watermark assigner into the scan. In some cases, query may have computed columns defined on rowtime column. If modifying the type of the rowtime(with time attribute), it will also influence the type of the computed column. Therefore, if the watermark assigner is not the parent of the scan, set the type of the scan as before and leave the work to projection.

supportsWatermarkPushDown

protected boolean supportsWatermarkPushDown(org.apache.flink.table.planner.plan.nodes.logical.FlinkLogicalTableSourceScan scan)