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

Class SubQueryDecorrelator.SubQueryRelDecorrelator

java.lang.Object

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

All Implemented Interfaces:

org.apache.calcite.util.ReflectiveVisitor

Enclosing class:

SubQueryDecorrelator

public static class SubQueryDecorrelator.SubQueryRelDecorrelator
extends Object
implements org.apache.calcite.util.ReflectiveVisitor

Pull out all correlation conditions from a given subquery to top level, and rebuild the subquery rel tree without correlation conditions.

`public` is for reflection. We use ReflectiveVisitor instead of RelShuttle because RelShuttle returns RelNode.

Method Summary

Modifier and Type	Method and Description
org.apache.flink.table.planner.plan.rules.logical.SubQueryDecorrelator.Frame	decorrelateRel(org.apache.calcite.rel.logical.LogicalAggregate rel) Rewrites a LogicalAggregate.
org.apache.flink.table.planner.plan.rules.logical.SubQueryDecorrelator.Frame	decorrelateRel(org.apache.calcite.rel.logical.LogicalCorrelate rel)
org.apache.flink.table.planner.plan.rules.logical.SubQueryDecorrelator.Frame	decorrelateRel(org.apache.calcite.rel.logical.LogicalFilter rel) Rewrite LogicalFilter.
org.apache.flink.table.planner.plan.rules.logical.SubQueryDecorrelator.Frame	decorrelateRel(org.apache.calcite.rel.logical.LogicalJoin rel) Rewrite LogicalJoin.
org.apache.flink.table.planner.plan.rules.logical.SubQueryDecorrelator.Frame	decorrelateRel(org.apache.calcite.rel.logical.LogicalProject rel) Rewrite LogicalProject.
org.apache.flink.table.planner.plan.rules.logical.SubQueryDecorrelator.Frame	decorrelateRel(org.apache.calcite.rel.RelNode rel) Fallback if none of the other decorrelateRel methods match.
org.apache.flink.table.planner.plan.rules.logical.SubQueryDecorrelator.Frame	decorrelateRel(org.apache.calcite.rel.core.Sort rel) Rewrite Sort.
org.apache.flink.table.planner.plan.rules.logical.SubQueryDecorrelator.Frame	decorrelateRel(org.apache.calcite.rel.core.Values rel) Rewrites a Values.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

decorrelateRel

public org.apache.flink.table.planner.plan.rules.logical.SubQueryDecorrelator.Frame decorrelateRel(org.apache.calcite.rel.logical.LogicalProject rel)

Rewrite LogicalProject.

Rewrite logic: Pass along any correlated variables coming from the input.

Parameters:

rel - the project rel to rewrite

decorrelateRel

public org.apache.flink.table.planner.plan.rules.logical.SubQueryDecorrelator.Frame decorrelateRel(org.apache.calcite.rel.logical.LogicalFilter rel)

Rewrite LogicalFilter.

Rewrite logic: 1. If a Filter references a correlated field in its filter condition, rewrite the Filter references only non-correlated fields, and the condition references correlated fields will be push to it's output. 2. If Filter does not reference correlated variables, simply rewrite the filter condition using new input.

Parameters:

rel - the filter rel to rewrite

decorrelateRel

public org.apache.flink.table.planner.plan.rules.logical.SubQueryDecorrelator.Frame decorrelateRel(org.apache.calcite.rel.logical.LogicalAggregate rel)

Rewrites a LogicalAggregate.

Rewrite logic: 1. Permute the group by keys to the front. 2. If the input of an aggregate produces correlated variables, add them to the group list. 3. Change aggCalls to reference the new project.

Parameters:

rel - Aggregate to rewrite

decorrelateRel

public org.apache.flink.table.planner.plan.rules.logical.SubQueryDecorrelator.Frame decorrelateRel(org.apache.calcite.rel.logical.LogicalJoin rel)

Rewrite LogicalJoin.

Rewrite logic: 1. rewrite join condition. 2. map output positions and produce corVars if any.

Parameters:

rel - Join

decorrelateRel

public org.apache.flink.table.planner.plan.rules.logical.SubQueryDecorrelator.Frame decorrelateRel(org.apache.calcite.rel.core.Sort rel)

Rewrite Sort.

Rewrite logic: change the collations field to reference the new input.

Parameters:

rel - Sort to be rewritten

decorrelateRel

public org.apache.flink.table.planner.plan.rules.logical.SubQueryDecorrelator.Frame decorrelateRel(org.apache.calcite.rel.core.Values rel)

Rewrites a Values.

Parameters:

rel - Values to be rewritten

decorrelateRel

public org.apache.flink.table.planner.plan.rules.logical.SubQueryDecorrelator.Frame decorrelateRel(org.apache.calcite.rel.logical.LogicalCorrelate rel)

decorrelateRel

public org.apache.flink.table.planner.plan.rules.logical.SubQueryDecorrelator.Frame decorrelateRel(org.apache.calcite.rel.RelNode rel)

Fallback if none of the other decorrelateRel methods match.