| /* |
| * 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 java.util.Map; |
| 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.Schema; |
| import org.apache.beam.sdk.schemas.SchemaCoder; |
| import org.apache.beam.sdk.transforms.PTransform; |
| import org.apache.beam.sdk.transforms.ParDo; |
| import org.apache.beam.sdk.transforms.View; |
| import org.apache.beam.sdk.values.KV; |
| import org.apache.beam.sdk.values.PCollection; |
| import org.apache.beam.sdk.values.PCollectionList; |
| import org.apache.beam.sdk.values.PCollectionView; |
| import org.apache.beam.sdk.values.Row; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.plan.RelOptCluster; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.plan.RelTraitSet; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.rel.RelNode; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.rel.core.CorrelationId; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.rel.core.Join; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.rel.core.JoinRelType; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.rex.RexNode; |
| |
| /** |
| * A {@code BeamJoinRel} which does sideinput Join |
| * |
| * <p>This Join Covers the case: |
| * |
| * <ul> |
| * <li>BoundedTable JOIN UnboundedTable |
| * </ul> |
| * |
| * <p>{@code sideInput} is utilized to implement the join, so there are some constraints: |
| * |
| * <ul> |
| * <li>{@code FULL OUTER JOIN} is not supported. |
| * <li>If it's a {@code LEFT OUTER JOIN}, the unbounded table should on the left side. |
| * <li>If it's a {@code RIGHT OUTER JOIN}, the unbounded table should on the right side. |
| * </ul> |
| * |
| * <p>General constraints: |
| * |
| * <ul> |
| * <li>Only equi-join is supported. |
| * <li>CROSS JOIN is not supported. |
| * </ul> |
| */ |
| public class BeamSideInputJoinRel extends BeamJoinRel { |
| |
| public BeamSideInputJoinRel( |
| 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 Join copy( |
| RelTraitSet traitSet, |
| RexNode conditionExpr, |
| RelNode left, |
| RelNode right, |
| JoinRelType joinType, |
| boolean semiJoinDone) { |
| return new BeamSideInputJoinRel( |
| getCluster(), traitSet, left, right, conditionExpr, variablesSet, joinType); |
| } |
| |
| @Override |
| public PTransform<PCollectionList<Row>, PCollection<Row>> buildPTransform() { |
| // if one of the sides is Bounded & the other is Unbounded |
| // then do a sideInput join. |
| // When doing a sideInput join, the windowFn does not need to match. |
| // Only support INNER JOIN & LEFT OUTER JOIN where left side of the join must be |
| // the unbounded & RIGHT OUTER JOIN where right side of the join must be the unbounded |
| if (joinType == JoinRelType.FULL) { |
| throw new UnsupportedOperationException( |
| "FULL OUTER JOIN is not supported when join " |
| + "a bounded table with an unbounded table."); |
| } |
| |
| BeamRelNode leftRelNode = BeamSqlRelUtils.getBeamRelInput(left); |
| BeamRelNode rightRelNode = BeamSqlRelUtils.getBeamRelInput(right); |
| |
| if ((joinType == JoinRelType.LEFT && leftRelNode.isBounded() == PCollection.IsBounded.BOUNDED) |
| || (joinType == JoinRelType.RIGHT |
| && rightRelNode.isBounded() == PCollection.IsBounded.BOUNDED)) { |
| throw new UnsupportedOperationException( |
| String.format("%s side of an OUTER JOIN must be Unbounded table.", joinType.name())); |
| } |
| return new SideInputJoin(); |
| } |
| |
| private class SideInputJoin extends PTransform<PCollectionList<Row>, PCollection<Row>> { |
| |
| @Override |
| public PCollection<Row> expand(PCollectionList<Row> pinput) { |
| Schema leftSchema = CalciteUtils.toSchema(left.getRowType()); |
| Schema rightSchema = CalciteUtils.toSchema(right.getRowType()); |
| |
| PCollectionList<KV<Row, Row>> keyedInputs = pinput.apply(new ExtractJoinKeys()); |
| |
| PCollection<KV<Row, Row>> extractedLeftRows = keyedInputs.get(0); |
| PCollection<KV<Row, Row>> extractedRightRows = keyedInputs.get(1); |
| |
| return sideInputJoin(extractedLeftRows, extractedRightRows, leftSchema, rightSchema); |
| } |
| } |
| |
| public PCollection<Row> sideInputJoin( |
| PCollection<KV<Row, Row>> extractedLeftRows, |
| PCollection<KV<Row, Row>> extractedRightRows, |
| Schema leftSchema, |
| Schema rightSchema) { |
| // we always make the Unbounded table on the left to do the sideInput join |
| // (will convert the result accordingly before return) |
| boolean swapped = (extractedLeftRows.isBounded() == PCollection.IsBounded.BOUNDED); |
| JoinRelType realJoinType = |
| (swapped && joinType != JoinRelType.INNER) ? JoinRelType.LEFT : joinType; |
| |
| PCollection<KV<Row, Row>> realLeftRows = swapped ? extractedRightRows : extractedLeftRows; |
| PCollection<KV<Row, Row>> realRightRows = swapped ? extractedLeftRows : extractedRightRows; |
| |
| Row realRightNullRow; |
| if (swapped) { |
| Schema leftNullSchema = buildNullSchema(leftSchema); |
| |
| realRightRows = BeamJoinRel.setValueCoder(realRightRows, SchemaCoder.of(leftNullSchema)); |
| realRightNullRow = Row.nullRow(leftNullSchema); |
| } else { |
| Schema rightNullSchema = buildNullSchema(rightSchema); |
| |
| realRightRows = BeamJoinRel.setValueCoder(realRightRows, SchemaCoder.of(rightNullSchema)); |
| realRightNullRow = Row.nullRow(rightNullSchema); |
| } |
| |
| // swapped still need to pass down because, we need to swap the result back. |
| return sideInputJoinHelper( |
| realJoinType, realLeftRows, realRightRows, realRightNullRow, swapped); |
| } |
| |
| private PCollection<Row> sideInputJoinHelper( |
| JoinRelType joinType, |
| PCollection<KV<Row, Row>> leftRows, |
| PCollection<KV<Row, Row>> rightRows, |
| Row rightNullRow, |
| boolean swapped) { |
| final PCollectionView<Map<Row, Iterable<Row>>> rowsView = rightRows.apply(View.asMultimap()); |
| |
| Schema schema = CalciteUtils.toSchema(getRowType()); |
| return leftRows |
| .apply( |
| ParDo.of( |
| new BeamJoinTransforms.SideInputJoinDoFn( |
| joinType, rightNullRow, rowsView, swapped, schema)) |
| .withSideInputs(rowsView)) |
| .setRowSchema(schema); |
| } |
| } |