liuyongvs commented on code in PR #24543: URL: https://github.com/apache/flink/pull/24543#discussion_r1899318955
########## flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/plan/rules/logical/FlinkRewriteSubQueryRule.java: ########## @@ -0,0 +1,195 @@ +/* + * 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.flink.table.planner.plan.rules.logical; + +import org.apache.calcite.plan.RelOptRuleCall; +import org.apache.calcite.plan.RelRule; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.core.Aggregate; +import org.apache.calcite.rel.core.AggregateCall; +import org.apache.calcite.rel.core.Filter; +import org.apache.calcite.rel.core.RelFactories; +import org.apache.calcite.rel.rules.SubQueryRemoveRule; +import org.apache.calcite.rex.RexCall; +import org.apache.calcite.rex.RexLiteral; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.rex.RexShuttle; +import org.apache.calcite.rex.RexSubQuery; +import org.apache.calcite.rex.RexUtil; +import org.apache.calcite.sql.SqlKind; +import org.apache.calcite.sql.fun.SqlCountAggFunction; +import org.apache.calcite.sql.type.SqlTypeFamily; +import org.immutables.value.Value; + +import java.util.Optional; + +/** + * Planner rule that rewrites scalar query in filter like: {@code select * from T1 where (select + * count(*) from T2) > 0} to {@code select * from T1 where exists (select * from T2)}, which could + * be converted to SEMI join by {@link FlinkSubQueryRemoveRule}. + * + * <p>Without this rule, the original query will be rewritten to a filter on a join on an aggregate + * by {@link SubQueryRemoveRule}. the full logical plan is + * + * <pre>{@code + * LogicalProject(a=[$0], b=[$1], c=[$2]) + * +- LogicalJoin(condition=[$3], joinType=[semi]) + * :- LogicalTableScan(table=[[x, source: [TestTableSource(a, b, c)]]]) + * +- LogicalProject($f0=[IS NOT NULL($0)]) + * +- LogicalAggregate(group=[{}], m=[MIN($0)]) + * +- LogicalProject(i=[true]) + * +- LogicalTableScan(table=[[y, source: [TestTableSource(d, e, f)]]]) + * }</pre> + */ +@Value.Enclosing +public class FlinkRewriteSubQueryRule + extends RelRule<FlinkRewriteSubQueryRule.FlinkRewriteSubQueryRuleConfig> { + + public static final FlinkRewriteSubQueryRule FILTER = + FlinkRewriteSubQueryRuleConfig.DEFAULT.toRule(); + + protected FlinkRewriteSubQueryRule( + FlinkRewriteSubQueryRule.FlinkRewriteSubQueryRuleConfig config) { + super(config); + } + + @Override + public void onMatch(RelOptRuleCall call) { + Filter filter = call.rel(0); + RexNode condition = filter.getCondition(); + RexNode newCondition = rewriteScalarQuery(condition); + if (condition.equals(newCondition)) { + return; + } + + Filter newFilter = filter.copy(filter.getTraitSet(), filter.getInput(), newCondition); + call.transformTo(newFilter); + } + + // scalar query like: `(select count(*) from T) > 0` can be converted to `exists(select * from + // T)` + private RexNode rewriteScalarQuery(RexNode condition) { + return condition.accept( + new RexShuttle() { + public RexNode visitCall(RexCall call) { + Optional<RexSubQuery> subQuery = getSupportedScalarQuery(call); + if (subQuery.isPresent()) { + return RexSubQuery.exists(subQuery.get().rel.getInput(0)); + } + return super.visitCall(call); + } + }); + } + + private boolean isScalarQuery(RexNode n) { + return n.isA(SqlKind.SCALAR_QUERY); + } + + private boolean isBetween0And1(RexNode n, boolean include0, boolean include1) { + if (n instanceof RexLiteral) { + RexLiteral l = (RexLiteral) n; + if (l.getTypeName().getFamily() == SqlTypeFamily.NUMERIC && l.getValue() != null) { + double v = Double.parseDouble(l.getValue().toString()); + return (0.0 < v && v < 1.0) || (include0 && v == 0.0) || (include1 && v == 1.0); + } + } + return false; + } + + private boolean isCountStarAggWithoutGroupBy(RelNode n) { + if (n instanceof Aggregate) { + Aggregate agg = (Aggregate) n; + if (agg.getGroupCount() == 0 && agg.getAggCallList().size() == 1) { + AggregateCall aggCall = agg.getAggCallList().get(0); + return !aggCall.isDistinct() + && aggCall.filterArg < 0 + && aggCall.getArgList().isEmpty() + && aggCall.getAggregation() instanceof SqlCountAggFunction; + } + } + return false; + } + + Optional<RexSubQuery> getSupportedScalarQuery(RexCall call) { + // check the RexNode is a RexLiteral which's value is between 0 and 1 + + // check the RelNode is a Aggregate which has only count aggregate call with empty args + + switch (call.getKind()) { + // (select count(*) from T) > X (X is between 0 (inclusive) and 1 (exclusive)) + case GREATER_THAN: + if (isScalarQuery(call.operands.get(0))) { + RexSubQuery subQuery = (RexSubQuery) call.operands.get(0); + if (isCountStarAggWithoutGroupBy(subQuery.rel) + && isBetween0And1(call.operands.get(1), true, false)) { + return Optional.of(subQuery); + } + } + break; + case GREATER_THAN_OR_EQUAL: + if (isScalarQuery(call.operands.get(0))) { + RexSubQuery subQuery = (RexSubQuery) call.operands.get(0); + if (isCountStarAggWithoutGroupBy(subQuery.rel) + && isBetween0And1(call.operands.get(1), false, true)) { + return Optional.of(subQuery); + } + } + break; + case LESS_THAN: Review Comment: add this comment // X < (select count(*) from T) (X is between 0 (inclusive) and 1 (exclusive)) ########## flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/plan/rules/logical/FlinkRewriteSubQueryRule.java: ########## @@ -0,0 +1,195 @@ +/* + * 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.flink.table.planner.plan.rules.logical; + +import org.apache.calcite.plan.RelOptRuleCall; +import org.apache.calcite.plan.RelRule; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.core.Aggregate; +import org.apache.calcite.rel.core.AggregateCall; +import org.apache.calcite.rel.core.Filter; +import org.apache.calcite.rel.core.RelFactories; +import org.apache.calcite.rel.rules.SubQueryRemoveRule; +import org.apache.calcite.rex.RexCall; +import org.apache.calcite.rex.RexLiteral; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.rex.RexShuttle; +import org.apache.calcite.rex.RexSubQuery; +import org.apache.calcite.rex.RexUtil; +import org.apache.calcite.sql.SqlKind; +import org.apache.calcite.sql.fun.SqlCountAggFunction; +import org.apache.calcite.sql.type.SqlTypeFamily; +import org.immutables.value.Value; + +import java.util.Optional; + +/** + * Planner rule that rewrites scalar query in filter like: {@code select * from T1 where (select + * count(*) from T2) > 0} to {@code select * from T1 where exists (select * from T2)}, which could + * be converted to SEMI join by {@link FlinkSubQueryRemoveRule}. + * + * <p>Without this rule, the original query will be rewritten to a filter on a join on an aggregate + * by {@link SubQueryRemoveRule}. the full logical plan is + * + * <pre>{@code + * LogicalProject(a=[$0], b=[$1], c=[$2]) + * +- LogicalJoin(condition=[$3], joinType=[semi]) + * :- LogicalTableScan(table=[[x, source: [TestTableSource(a, b, c)]]]) + * +- LogicalProject($f0=[IS NOT NULL($0)]) + * +- LogicalAggregate(group=[{}], m=[MIN($0)]) + * +- LogicalProject(i=[true]) + * +- LogicalTableScan(table=[[y, source: [TestTableSource(d, e, f)]]]) + * }</pre> + */ +@Value.Enclosing +public class FlinkRewriteSubQueryRule + extends RelRule<FlinkRewriteSubQueryRule.FlinkRewriteSubQueryRuleConfig> { + + public static final FlinkRewriteSubQueryRule FILTER = + FlinkRewriteSubQueryRuleConfig.DEFAULT.toRule(); + + protected FlinkRewriteSubQueryRule( + FlinkRewriteSubQueryRule.FlinkRewriteSubQueryRuleConfig config) { + super(config); + } + + @Override + public void onMatch(RelOptRuleCall call) { + Filter filter = call.rel(0); + RexNode condition = filter.getCondition(); + RexNode newCondition = rewriteScalarQuery(condition); + if (condition.equals(newCondition)) { + return; + } + + Filter newFilter = filter.copy(filter.getTraitSet(), filter.getInput(), newCondition); + call.transformTo(newFilter); + } + + // scalar query like: `(select count(*) from T) > 0` can be converted to `exists(select * from + // T)` + private RexNode rewriteScalarQuery(RexNode condition) { + return condition.accept( + new RexShuttle() { + public RexNode visitCall(RexCall call) { + Optional<RexSubQuery> subQuery = getSupportedScalarQuery(call); + if (subQuery.isPresent()) { + return RexSubQuery.exists(subQuery.get().rel.getInput(0)); + } + return super.visitCall(call); + } + }); + } + + private boolean isScalarQuery(RexNode n) { + return n.isA(SqlKind.SCALAR_QUERY); + } + + private boolean isBetween0And1(RexNode n, boolean include0, boolean include1) { + if (n instanceof RexLiteral) { + RexLiteral l = (RexLiteral) n; + if (l.getTypeName().getFamily() == SqlTypeFamily.NUMERIC && l.getValue() != null) { + double v = Double.parseDouble(l.getValue().toString()); + return (0.0 < v && v < 1.0) || (include0 && v == 0.0) || (include1 && v == 1.0); + } + } + return false; + } + + private boolean isCountStarAggWithoutGroupBy(RelNode n) { + if (n instanceof Aggregate) { + Aggregate agg = (Aggregate) n; + if (agg.getGroupCount() == 0 && agg.getAggCallList().size() == 1) { + AggregateCall aggCall = agg.getAggCallList().get(0); + return !aggCall.isDistinct() + && aggCall.filterArg < 0 + && aggCall.getArgList().isEmpty() + && aggCall.getAggregation() instanceof SqlCountAggFunction; + } + } + return false; + } + + Optional<RexSubQuery> getSupportedScalarQuery(RexCall call) { + // check the RexNode is a RexLiteral which's value is between 0 and 1 + + // check the RelNode is a Aggregate which has only count aggregate call with empty args + + switch (call.getKind()) { + // (select count(*) from T) > X (X is between 0 (inclusive) and 1 (exclusive)) + case GREATER_THAN: + if (isScalarQuery(call.operands.get(0))) { + RexSubQuery subQuery = (RexSubQuery) call.operands.get(0); + if (isCountStarAggWithoutGroupBy(subQuery.rel) + && isBetween0And1(call.operands.get(1), true, false)) { + return Optional.of(subQuery); + } + } + break; + case GREATER_THAN_OR_EQUAL: + if (isScalarQuery(call.operands.get(0))) { + RexSubQuery subQuery = (RexSubQuery) call.operands.get(0); + if (isCountStarAggWithoutGroupBy(subQuery.rel) + && isBetween0And1(call.operands.get(1), false, true)) { + return Optional.of(subQuery); + } + } + break; + case LESS_THAN: + if (isScalarQuery(call.operands.get(1))) { + RexSubQuery subQuery = (RexSubQuery) call.operands.get(1); + if (isCountStarAggWithoutGroupBy(subQuery.rel) + && isBetween0And1(call.operands.get(0), true, false)) { + return Optional.of(subQuery); + } + } + break; Review Comment: add this comment // X <= (select count(*) from T) (X is between 0 (exclusive) and 1 (inclusive)) ########## flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/plan/rules/logical/FlinkRewriteSubQueryRule.java: ########## @@ -0,0 +1,195 @@ +/* + * 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.flink.table.planner.plan.rules.logical; + +import org.apache.calcite.plan.RelOptRuleCall; +import org.apache.calcite.plan.RelRule; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.core.Aggregate; +import org.apache.calcite.rel.core.AggregateCall; +import org.apache.calcite.rel.core.Filter; +import org.apache.calcite.rel.core.RelFactories; +import org.apache.calcite.rel.rules.SubQueryRemoveRule; +import org.apache.calcite.rex.RexCall; +import org.apache.calcite.rex.RexLiteral; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.rex.RexShuttle; +import org.apache.calcite.rex.RexSubQuery; +import org.apache.calcite.rex.RexUtil; +import org.apache.calcite.sql.SqlKind; +import org.apache.calcite.sql.fun.SqlCountAggFunction; +import org.apache.calcite.sql.type.SqlTypeFamily; +import org.immutables.value.Value; + +import java.util.Optional; + +/** + * Planner rule that rewrites scalar query in filter like: {@code select * from T1 where (select + * count(*) from T2) > 0} to {@code select * from T1 where exists (select * from T2)}, which could + * be converted to SEMI join by {@link FlinkSubQueryRemoveRule}. + * + * <p>Without this rule, the original query will be rewritten to a filter on a join on an aggregate + * by {@link SubQueryRemoveRule}. the full logical plan is + * + * <pre>{@code + * LogicalProject(a=[$0], b=[$1], c=[$2]) + * +- LogicalJoin(condition=[$3], joinType=[semi]) + * :- LogicalTableScan(table=[[x, source: [TestTableSource(a, b, c)]]]) + * +- LogicalProject($f0=[IS NOT NULL($0)]) + * +- LogicalAggregate(group=[{}], m=[MIN($0)]) + * +- LogicalProject(i=[true]) + * +- LogicalTableScan(table=[[y, source: [TestTableSource(d, e, f)]]]) + * }</pre> + */ +@Value.Enclosing +public class FlinkRewriteSubQueryRule + extends RelRule<FlinkRewriteSubQueryRule.FlinkRewriteSubQueryRuleConfig> { + + public static final FlinkRewriteSubQueryRule FILTER = + FlinkRewriteSubQueryRuleConfig.DEFAULT.toRule(); + + protected FlinkRewriteSubQueryRule( + FlinkRewriteSubQueryRule.FlinkRewriteSubQueryRuleConfig config) { + super(config); + } + + @Override + public void onMatch(RelOptRuleCall call) { + Filter filter = call.rel(0); + RexNode condition = filter.getCondition(); + RexNode newCondition = rewriteScalarQuery(condition); + if (condition.equals(newCondition)) { + return; + } + + Filter newFilter = filter.copy(filter.getTraitSet(), filter.getInput(), newCondition); + call.transformTo(newFilter); + } + + // scalar query like: `(select count(*) from T) > 0` can be converted to `exists(select * from + // T)` + private RexNode rewriteScalarQuery(RexNode condition) { + return condition.accept( + new RexShuttle() { + public RexNode visitCall(RexCall call) { + Optional<RexSubQuery> subQuery = getSupportedScalarQuery(call); + if (subQuery.isPresent()) { + return RexSubQuery.exists(subQuery.get().rel.getInput(0)); + } + return super.visitCall(call); + } + }); + } + + private boolean isScalarQuery(RexNode n) { + return n.isA(SqlKind.SCALAR_QUERY); + } + + private boolean isBetween0And1(RexNode n, boolean include0, boolean include1) { + if (n instanceof RexLiteral) { + RexLiteral l = (RexLiteral) n; + if (l.getTypeName().getFamily() == SqlTypeFamily.NUMERIC && l.getValue() != null) { + double v = Double.parseDouble(l.getValue().toString()); + return (0.0 < v && v < 1.0) || (include0 && v == 0.0) || (include1 && v == 1.0); + } + } + return false; + } + Review Comment: add this comment // check the RelNode is a Aggregate which has only count aggregate call with empty args ########## flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/plan/rules/logical/FlinkRewriteSubQueryRule.java: ########## @@ -0,0 +1,195 @@ +/* + * 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.flink.table.planner.plan.rules.logical; + +import org.apache.calcite.plan.RelOptRuleCall; +import org.apache.calcite.plan.RelRule; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.core.Aggregate; +import org.apache.calcite.rel.core.AggregateCall; +import org.apache.calcite.rel.core.Filter; +import org.apache.calcite.rel.core.RelFactories; +import org.apache.calcite.rel.rules.SubQueryRemoveRule; +import org.apache.calcite.rex.RexCall; +import org.apache.calcite.rex.RexLiteral; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.rex.RexShuttle; +import org.apache.calcite.rex.RexSubQuery; +import org.apache.calcite.rex.RexUtil; +import org.apache.calcite.sql.SqlKind; +import org.apache.calcite.sql.fun.SqlCountAggFunction; +import org.apache.calcite.sql.type.SqlTypeFamily; +import org.immutables.value.Value; + +import java.util.Optional; + +/** + * Planner rule that rewrites scalar query in filter like: {@code select * from T1 where (select + * count(*) from T2) > 0} to {@code select * from T1 where exists (select * from T2)}, which could + * be converted to SEMI join by {@link FlinkSubQueryRemoveRule}. + * + * <p>Without this rule, the original query will be rewritten to a filter on a join on an aggregate + * by {@link SubQueryRemoveRule}. the full logical plan is + * + * <pre>{@code + * LogicalProject(a=[$0], b=[$1], c=[$2]) + * +- LogicalJoin(condition=[$3], joinType=[semi]) + * :- LogicalTableScan(table=[[x, source: [TestTableSource(a, b, c)]]]) + * +- LogicalProject($f0=[IS NOT NULL($0)]) + * +- LogicalAggregate(group=[{}], m=[MIN($0)]) + * +- LogicalProject(i=[true]) + * +- LogicalTableScan(table=[[y, source: [TestTableSource(d, e, f)]]]) + * }</pre> + */ +@Value.Enclosing +public class FlinkRewriteSubQueryRule + extends RelRule<FlinkRewriteSubQueryRule.FlinkRewriteSubQueryRuleConfig> { + + public static final FlinkRewriteSubQueryRule FILTER = + FlinkRewriteSubQueryRuleConfig.DEFAULT.toRule(); + + protected FlinkRewriteSubQueryRule( + FlinkRewriteSubQueryRule.FlinkRewriteSubQueryRuleConfig config) { + super(config); + } + + @Override + public void onMatch(RelOptRuleCall call) { + Filter filter = call.rel(0); + RexNode condition = filter.getCondition(); + RexNode newCondition = rewriteScalarQuery(condition); + if (condition.equals(newCondition)) { + return; + } + + Filter newFilter = filter.copy(filter.getTraitSet(), filter.getInput(), newCondition); + call.transformTo(newFilter); + } + + // scalar query like: `(select count(*) from T) > 0` can be converted to `exists(select * from + // T)` + private RexNode rewriteScalarQuery(RexNode condition) { + return condition.accept( + new RexShuttle() { + public RexNode visitCall(RexCall call) { + Optional<RexSubQuery> subQuery = getSupportedScalarQuery(call); + if (subQuery.isPresent()) { + return RexSubQuery.exists(subQuery.get().rel.getInput(0)); + } + return super.visitCall(call); + } + }); + } + + private boolean isScalarQuery(RexNode n) { + return n.isA(SqlKind.SCALAR_QUERY); + } + Review Comment: add this comment // check the RexNode is a RexLiteral which's value is between 0 and 1 ########## flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/plan/rules/logical/FlinkRewriteSubQueryRule.java: ########## @@ -0,0 +1,195 @@ +/* + * 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.flink.table.planner.plan.rules.logical; + +import org.apache.calcite.plan.RelOptRuleCall; +import org.apache.calcite.plan.RelRule; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.core.Aggregate; +import org.apache.calcite.rel.core.AggregateCall; +import org.apache.calcite.rel.core.Filter; +import org.apache.calcite.rel.core.RelFactories; +import org.apache.calcite.rel.rules.SubQueryRemoveRule; +import org.apache.calcite.rex.RexCall; +import org.apache.calcite.rex.RexLiteral; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.rex.RexShuttle; +import org.apache.calcite.rex.RexSubQuery; +import org.apache.calcite.rex.RexUtil; +import org.apache.calcite.sql.SqlKind; +import org.apache.calcite.sql.fun.SqlCountAggFunction; +import org.apache.calcite.sql.type.SqlTypeFamily; +import org.immutables.value.Value; + +import java.util.Optional; + +/** + * Planner rule that rewrites scalar query in filter like: {@code select * from T1 where (select + * count(*) from T2) > 0} to {@code select * from T1 where exists (select * from T2)}, which could + * be converted to SEMI join by {@link FlinkSubQueryRemoveRule}. + * + * <p>Without this rule, the original query will be rewritten to a filter on a join on an aggregate + * by {@link SubQueryRemoveRule}. the full logical plan is + * + * <pre>{@code + * LogicalProject(a=[$0], b=[$1], c=[$2]) + * +- LogicalJoin(condition=[$3], joinType=[semi]) + * :- LogicalTableScan(table=[[x, source: [TestTableSource(a, b, c)]]]) + * +- LogicalProject($f0=[IS NOT NULL($0)]) + * +- LogicalAggregate(group=[{}], m=[MIN($0)]) + * +- LogicalProject(i=[true]) + * +- LogicalTableScan(table=[[y, source: [TestTableSource(d, e, f)]]]) + * }</pre> + */ +@Value.Enclosing +public class FlinkRewriteSubQueryRule + extends RelRule<FlinkRewriteSubQueryRule.FlinkRewriteSubQueryRuleConfig> { + + public static final FlinkRewriteSubQueryRule FILTER = + FlinkRewriteSubQueryRuleConfig.DEFAULT.toRule(); + + protected FlinkRewriteSubQueryRule( + FlinkRewriteSubQueryRule.FlinkRewriteSubQueryRuleConfig config) { + super(config); + } + + @Override + public void onMatch(RelOptRuleCall call) { + Filter filter = call.rel(0); + RexNode condition = filter.getCondition(); + RexNode newCondition = rewriteScalarQuery(condition); + if (condition.equals(newCondition)) { + return; + } + + Filter newFilter = filter.copy(filter.getTraitSet(), filter.getInput(), newCondition); + call.transformTo(newFilter); + } + + // scalar query like: `(select count(*) from T) > 0` can be converted to `exists(select * from + // T)` + private RexNode rewriteScalarQuery(RexNode condition) { + return condition.accept( + new RexShuttle() { + public RexNode visitCall(RexCall call) { + Optional<RexSubQuery> subQuery = getSupportedScalarQuery(call); + if (subQuery.isPresent()) { + return RexSubQuery.exists(subQuery.get().rel.getInput(0)); + } + return super.visitCall(call); + } + }); + } + + private boolean isScalarQuery(RexNode n) { + return n.isA(SqlKind.SCALAR_QUERY); + } + + private boolean isBetween0And1(RexNode n, boolean include0, boolean include1) { + if (n instanceof RexLiteral) { + RexLiteral l = (RexLiteral) n; + if (l.getTypeName().getFamily() == SqlTypeFamily.NUMERIC && l.getValue() != null) { + double v = Double.parseDouble(l.getValue().toString()); + return (0.0 < v && v < 1.0) || (include0 && v == 0.0) || (include1 && v == 1.0); + } + } + return false; + } + + private boolean isCountStarAggWithoutGroupBy(RelNode n) { + if (n instanceof Aggregate) { + Aggregate agg = (Aggregate) n; + if (agg.getGroupCount() == 0 && agg.getAggCallList().size() == 1) { + AggregateCall aggCall = agg.getAggCallList().get(0); + return !aggCall.isDistinct() + && aggCall.filterArg < 0 + && aggCall.getArgList().isEmpty() + && aggCall.getAggregation() instanceof SqlCountAggFunction; + } + } + return false; + } + + Optional<RexSubQuery> getSupportedScalarQuery(RexCall call) { + // check the RexNode is a RexLiteral which's value is between 0 and 1 + + // check the RelNode is a Aggregate which has only count aggregate call with empty args + + switch (call.getKind()) { + // (select count(*) from T) > X (X is between 0 (inclusive) and 1 (exclusive)) + case GREATER_THAN: + if (isScalarQuery(call.operands.get(0))) { + RexSubQuery subQuery = (RexSubQuery) call.operands.get(0); + if (isCountStarAggWithoutGroupBy(subQuery.rel) + && isBetween0And1(call.operands.get(1), true, false)) { + return Optional.of(subQuery); + } + } + break; Review Comment: add this comment // (select count(*) from T) >= X (X is between 0 (exclusive) and 1 (inclusive)) ########## flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/plan/rules/logical/FlinkRewriteSubQueryRule.java: ########## @@ -0,0 +1,195 @@ +/* + * 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.flink.table.planner.plan.rules.logical; + +import org.apache.calcite.plan.RelOptRuleCall; +import org.apache.calcite.plan.RelRule; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.core.Aggregate; +import org.apache.calcite.rel.core.AggregateCall; +import org.apache.calcite.rel.core.Filter; +import org.apache.calcite.rel.core.RelFactories; +import org.apache.calcite.rel.rules.SubQueryRemoveRule; +import org.apache.calcite.rex.RexCall; +import org.apache.calcite.rex.RexLiteral; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.rex.RexShuttle; +import org.apache.calcite.rex.RexSubQuery; +import org.apache.calcite.rex.RexUtil; +import org.apache.calcite.sql.SqlKind; +import org.apache.calcite.sql.fun.SqlCountAggFunction; +import org.apache.calcite.sql.type.SqlTypeFamily; +import org.immutables.value.Value; + +import java.util.Optional; + +/** + * Planner rule that rewrites scalar query in filter like: {@code select * from T1 where (select + * count(*) from T2) > 0} to {@code select * from T1 where exists (select * from T2)}, which could + * be converted to SEMI join by {@link FlinkSubQueryRemoveRule}. + * + * <p>Without this rule, the original query will be rewritten to a filter on a join on an aggregate + * by {@link SubQueryRemoveRule}. the full logical plan is + * + * <pre>{@code + * LogicalProject(a=[$0], b=[$1], c=[$2]) + * +- LogicalJoin(condition=[$3], joinType=[semi]) + * :- LogicalTableScan(table=[[x, source: [TestTableSource(a, b, c)]]]) + * +- LogicalProject($f0=[IS NOT NULL($0)]) + * +- LogicalAggregate(group=[{}], m=[MIN($0)]) + * +- LogicalProject(i=[true]) + * +- LogicalTableScan(table=[[y, source: [TestTableSource(d, e, f)]]]) + * }</pre> + */ +@Value.Enclosing +public class FlinkRewriteSubQueryRule + extends RelRule<FlinkRewriteSubQueryRule.FlinkRewriteSubQueryRuleConfig> { + + public static final FlinkRewriteSubQueryRule FILTER = + FlinkRewriteSubQueryRuleConfig.DEFAULT.toRule(); + + protected FlinkRewriteSubQueryRule( + FlinkRewriteSubQueryRule.FlinkRewriteSubQueryRuleConfig config) { + super(config); + } + + @Override + public void onMatch(RelOptRuleCall call) { + Filter filter = call.rel(0); + RexNode condition = filter.getCondition(); + RexNode newCondition = rewriteScalarQuery(condition); + if (condition.equals(newCondition)) { + return; + } + + Filter newFilter = filter.copy(filter.getTraitSet(), filter.getInput(), newCondition); + call.transformTo(newFilter); + } + + // scalar query like: `(select count(*) from T) > 0` can be converted to `exists(select * from + // T)` + private RexNode rewriteScalarQuery(RexNode condition) { + return condition.accept( + new RexShuttle() { + public RexNode visitCall(RexCall call) { + Optional<RexSubQuery> subQuery = getSupportedScalarQuery(call); + if (subQuery.isPresent()) { + return RexSubQuery.exists(subQuery.get().rel.getInput(0)); + } + return super.visitCall(call); + } + }); + } + + private boolean isScalarQuery(RexNode n) { + return n.isA(SqlKind.SCALAR_QUERY); + } + + private boolean isBetween0And1(RexNode n, boolean include0, boolean include1) { + if (n instanceof RexLiteral) { + RexLiteral l = (RexLiteral) n; + if (l.getTypeName().getFamily() == SqlTypeFamily.NUMERIC && l.getValue() != null) { + double v = Double.parseDouble(l.getValue().toString()); + return (0.0 < v && v < 1.0) || (include0 && v == 0.0) || (include1 && v == 1.0); + } + } + return false; + } + + private boolean isCountStarAggWithoutGroupBy(RelNode n) { + if (n instanceof Aggregate) { + Aggregate agg = (Aggregate) n; + if (agg.getGroupCount() == 0 && agg.getAggCallList().size() == 1) { + AggregateCall aggCall = agg.getAggCallList().get(0); + return !aggCall.isDistinct() + && aggCall.filterArg < 0 + && aggCall.getArgList().isEmpty() + && aggCall.getAggregation() instanceof SqlCountAggFunction; + } + } + return false; + } + + Optional<RexSubQuery> getSupportedScalarQuery(RexCall call) { + // check the RexNode is a RexLiteral which's value is between 0 and 1 + + // check the RelNode is a Aggregate which has only count aggregate call with empty args + Review Comment: remove the comments, because it adds // check the RexNode is a RexLiteral which's value is between 0 and 1 // check the RelNode is a Aggregate which has only count aggregate call with empty args -- This is an automated message from the Apache Git Service. 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