| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.beam.sdk.extensions.sql.impl.rel; |
| |
| import static org.apache.beam.sdk.values.PCollection.IsBounded.UNBOUNDED; |
| import static org.joda.time.Duration.ZERO; |
| |
| import java.util.List; |
| import java.util.Set; |
| import org.apache.beam.sdk.extensions.sql.impl.transform.BeamJoinTransforms; |
| import org.apache.beam.sdk.extensions.sql.impl.utils.CalciteUtils; |
| import org.apache.beam.sdk.schemas.FieldAccessDescriptor; |
| import org.apache.beam.sdk.schemas.Schema; |
| import org.apache.beam.sdk.schemas.transforms.Join.FieldsEqual; |
| import org.apache.beam.sdk.schemas.transforms.Select; |
| import org.apache.beam.sdk.transforms.PTransform; |
| import org.apache.beam.sdk.transforms.windowing.DefaultTrigger; |
| import org.apache.beam.sdk.transforms.windowing.GlobalWindows; |
| import org.apache.beam.sdk.transforms.windowing.IncompatibleWindowException; |
| import org.apache.beam.sdk.transforms.windowing.TimestampCombiner; |
| import org.apache.beam.sdk.transforms.windowing.Trigger; |
| import org.apache.beam.sdk.transforms.windowing.Window; |
| import org.apache.beam.sdk.transforms.windowing.WindowFn; |
| import org.apache.beam.sdk.values.PCollection; |
| import org.apache.beam.sdk.values.PCollectionList; |
| import org.apache.beam.sdk.values.Row; |
| import org.apache.beam.sdk.values.WindowingStrategy; |
| import org.apache.beam.vendor.calcite.v1_28_0.org.apache.calcite.plan.RelOptCluster; |
| import org.apache.beam.vendor.calcite.v1_28_0.org.apache.calcite.plan.RelTraitSet; |
| import org.apache.beam.vendor.calcite.v1_28_0.org.apache.calcite.rel.RelNode; |
| import org.apache.beam.vendor.calcite.v1_28_0.org.apache.calcite.rel.core.CorrelationId; |
| import org.apache.beam.vendor.calcite.v1_28_0.org.apache.calcite.rel.core.Join; |
| import org.apache.beam.vendor.calcite.v1_28_0.org.apache.calcite.rel.core.JoinRelType; |
| import org.apache.beam.vendor.calcite.v1_28_0.org.apache.calcite.rex.RexNode; |
| import org.apache.beam.vendor.calcite.v1_28_0.org.apache.calcite.util.Pair; |
| |
| /** |
| * A {@code BeamJoinRel} which does CoGBK Join |
| * |
| * <p>This Join Covers the cases: |
| * |
| * <ul> |
| * <li>BoundedTable JOIN BoundedTable |
| * <li>UnboundedTable JOIN UnboundedTable |
| * </ul> |
| * |
| * <p>A CoGBK join is utilized as long as the windowFn of the both sides match. For more info refer |
| * <a href="https://issues.apache.org/jira/browse/BEAM-3345">BEAM-3345</a> |
| * |
| * <p>General constraints: |
| * |
| * <ul> |
| * <li>Only equi-join is supported. |
| * <li>CROSS JOIN is not supported. |
| * </ul> |
| */ |
| @SuppressWarnings({ |
| "rawtypes" // TODO(https://github.com/apache/beam/issues/20447) |
| }) |
| public class BeamCoGBKJoinRel extends BeamJoinRel { |
| |
| public BeamCoGBKJoinRel( |
| RelOptCluster cluster, |
| RelTraitSet traitSet, |
| RelNode left, |
| RelNode right, |
| RexNode condition, |
| Set<CorrelationId> variablesSet, |
| JoinRelType joinType) { |
| super(cluster, traitSet, left, right, condition, variablesSet, joinType); |
| } |
| |
| @Override |
| public PTransform<PCollectionList<Row>, PCollection<Row>> buildPTransform() { |
| return new StandardJoin(); |
| } |
| |
| private class StandardJoin extends PTransform<PCollectionList<Row>, PCollection<Row>> { |
| |
| @Override |
| public PCollection<Row> expand(PCollectionList<Row> pinput) { |
| Schema leftSchema = pinput.get(0).getSchema(); |
| Schema rightSchema = pinput.get(1).getSchema(); |
| |
| PCollection<Row> leftRows = |
| pinput |
| .get(0) |
| .apply( |
| "left_TimestampCombiner", |
| Window.<Row>configure().withTimestampCombiner(TimestampCombiner.EARLIEST)); |
| PCollection<Row> rightRows = |
| pinput |
| .get(1) |
| .apply( |
| "right_TimestampCombiner", |
| Window.<Row>configure().withTimestampCombiner(TimestampCombiner.EARLIEST)); |
| |
| // extract the join fields |
| List<Pair<RexNode, RexNode>> pairs = extractJoinRexNodes(condition); |
| int leftRowColumnCount = BeamSqlRelUtils.getBeamRelInput(left).getRowType().getFieldCount(); |
| |
| FieldAccessDescriptor leftKeyFields = |
| BeamJoinTransforms.getJoinColumns(true, pairs, 0, leftSchema); |
| FieldAccessDescriptor rightKeyFields = |
| BeamJoinTransforms.getJoinColumns(false, pairs, leftRowColumnCount, rightSchema); |
| |
| WindowFn leftWinFn = leftRows.getWindowingStrategy().getWindowFn(); |
| WindowFn rightWinFn = rightRows.getWindowingStrategy().getWindowFn(); |
| |
| try { |
| leftWinFn.verifyCompatibility(rightWinFn); |
| } catch (IncompatibleWindowException e) { |
| throw new IllegalArgumentException( |
| "WindowFns must match for a bounded-vs-bounded/unbounded-vs-unbounded join.", e); |
| } |
| |
| verifySupportedTrigger(leftRows); |
| verifySupportedTrigger(rightRows); |
| |
| return standardJoin(leftRows, rightRows, leftKeyFields, rightKeyFields); |
| } |
| } |
| |
| private <T> void verifySupportedTrigger(PCollection<T> pCollection) { |
| WindowingStrategy windowingStrategy = pCollection.getWindowingStrategy(); |
| |
| if (UNBOUNDED.equals(pCollection.isBounded()) && !triggersOncePerWindow(windowingStrategy)) { |
| throw new UnsupportedOperationException( |
| "Joining unbounded PCollections is currently only supported for " |
| + "non-global windows with triggers that are known to produce output once per window," |
| + "such as the default trigger with zero allowed lateness. " |
| + "In these cases Beam can guarantee it joins all input elements once per window. " |
| + windowingStrategy |
| + " is not supported"); |
| } |
| } |
| |
| private boolean triggersOncePerWindow(WindowingStrategy windowingStrategy) { |
| Trigger trigger = windowingStrategy.getTrigger(); |
| |
| return !(windowingStrategy.getWindowFn() instanceof GlobalWindows) |
| && trigger instanceof DefaultTrigger |
| && ZERO.equals(windowingStrategy.getAllowedLateness()); |
| } |
| |
| private PCollection<Row> standardJoin( |
| PCollection<Row> leftRows, |
| PCollection<Row> rightRows, |
| FieldAccessDescriptor leftKeys, |
| FieldAccessDescriptor rightKeys) { |
| PCollection<Row> joinedRows = null; |
| |
| switch (joinType) { |
| case LEFT: |
| joinedRows = |
| leftRows.apply( |
| org.apache.beam.sdk.schemas.transforms.Join.<Row, Row>leftOuterJoin(rightRows) |
| .on(FieldsEqual.left(leftKeys).right(rightKeys))); |
| break; |
| case RIGHT: |
| joinedRows = |
| leftRows.apply( |
| org.apache.beam.sdk.schemas.transforms.Join.<Row, Row>rightOuterJoin(rightRows) |
| .on(FieldsEqual.left(leftKeys).right(rightKeys))); |
| break; |
| case FULL: |
| joinedRows = |
| leftRows.apply( |
| org.apache.beam.sdk.schemas.transforms.Join.<Row, Row>fullOuterJoin(rightRows) |
| .on(FieldsEqual.left(leftKeys).right(rightKeys))); |
| break; |
| case INNER: |
| default: |
| joinedRows = |
| leftRows.apply( |
| org.apache.beam.sdk.schemas.transforms.Join.<Row, Row>innerJoin(rightRows) |
| .on(FieldsEqual.left(leftKeys).right(rightKeys))); |
| } |
| |
| // Flatten the lhs and rhs fields into a single row. |
| return joinedRows.apply( |
| Select.<Row>fieldNames( |
| org.apache.beam.sdk.schemas.transforms.Join.LHS_TAG + ".*", |
| org.apache.beam.sdk.schemas.transforms.Join.RHS_TAG + ".*") |
| .withOutputSchema(CalciteUtils.toSchema(getRowType()))); |
| } |
| |
| @Override |
| public Join copy( |
| RelTraitSet traitSet, |
| RexNode conditionExpr, |
| RelNode left, |
| RelNode right, |
| JoinRelType joinType, |
| boolean semiJoinDone) { |
| return new BeamCoGBKJoinRel( |
| getCluster(), traitSet, left, right, conditionExpr, variablesSet, joinType); |
| } |
| } |
