924060929 commented on code in PR #66942: URL: https://github.com/apache/doris/pull/66942#discussion_r3849558486
########## fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/functions/combinator/CombineCombinator.java: ########## @@ -0,0 +1,164 @@ +// 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.doris.nereids.trees.expressions.functions.combinator; + +import org.apache.doris.catalog.BuiltinAggregateFunctions; +import org.apache.doris.catalog.Env; +import org.apache.doris.catalog.FunctionRegistry; +import org.apache.doris.catalog.FunctionSignature; +import org.apache.doris.common.Pair; +import org.apache.doris.nereids.exceptions.AnalysisException; +import org.apache.doris.nereids.trees.expressions.Expression; +import org.apache.doris.nereids.trees.expressions.OrderExpression; +import org.apache.doris.nereids.trees.expressions.functions.AggCombinerFunctionBuilder; +import org.apache.doris.nereids.trees.expressions.functions.AlwaysNotNullable; +import org.apache.doris.nereids.trees.expressions.functions.BoundFunction; +import org.apache.doris.nereids.trees.expressions.functions.ExplicitlyCastableSignature; +import org.apache.doris.nereids.trees.expressions.functions.ExpressionTrait; +import org.apache.doris.nereids.trees.expressions.functions.Function; +import org.apache.doris.nereids.trees.expressions.functions.FunctionBuilder; +import org.apache.doris.nereids.trees.expressions.functions.agg.AggregateFunction; +import org.apache.doris.nereids.trees.expressions.functions.agg.AggregateFunctionParams; +import org.apache.doris.nereids.trees.expressions.functions.agg.AggregatePhase; +import org.apache.doris.nereids.trees.expressions.functions.agg.RollUpTrait; +import org.apache.doris.nereids.trees.expressions.visitor.ExpressionVisitor; +import org.apache.doris.nereids.types.AggStateType; +import org.apache.doris.nereids.types.DataType; + +import com.google.common.collect.ImmutableList; + +import java.util.List; +import java.util.Objects; + +/** + * Aggregate inputs into the nested function's serialized state. + */ +public class CombineCombinator extends AggregateFunction + implements ExplicitlyCastableSignature, AlwaysNotNullable, Combinator, RollUpTrait { + + private final AggregateFunction nested; + private final AggStateType returnType; + + /** Constructor of CombineCombinator. */ + public CombineCombinator(List<Expression> arguments, AggregateFunction nested) { + super(nested.getName() + AggCombinerFunctionBuilder.COMBINE_SUFFIX, arguments); + checkArguments(arguments, nested); + this.nested = Objects.requireNonNull(nested, "nested can not be null"); + this.returnType = createReturnType(arguments, nested); + } + + private CombineCombinator(AggregateFunctionParams functionParams, AggregateFunction nested) { + super(functionParams); + checkArguments(functionParams.arguments, nested); + this.nested = Objects.requireNonNull(nested, "nested can not be null"); + this.returnType = createReturnType(functionParams.arguments, nested); + } + + private static void checkArguments(List<Expression> arguments, AggregateFunction nested) { + if (arguments.isEmpty()) { + throw new AnalysisException(String.format( + "%s_combine requires at least one argument", nested.getName())); + } + for (Expression argument : arguments) { + if (argument instanceof OrderExpression) { + throw new AnalysisException(String.format( + "%s_combine doesn't support order by expression", nested.getName())); + } + } + } + + private static AggStateType createReturnType(List<Expression> arguments, AggregateFunction nested) { + return new AggStateType(nested.getName(), + arguments.stream().map(ExpressionTrait::getDataType) + .collect(ImmutableList.toImmutableList()), + arguments.stream().map(ExpressionTrait::nullable) + .collect(ImmutableList.toImmutableList()), + BuiltinAggregateFunctions.INSTANCE.aggFuncNameNullableMap.get(nested.getName())); + } + + @Override + public CombineCombinator withChildren(List<Expression> children) { Review Comment: Requiring exact AggState equality is a possible feature boundary, and this does not necessarily require the producer-aware rewrite suggested above. However, the current implementation does not enforce that boundary consistently. Doris currently admits same-function/same-arity AggState coercion in `CheckCast.checkWithLooseAggState()`. Therefore explicit CAST and INSERT/sink binding can first accept the conversion and introduce `Cast(combine_slot AS target)`, but it is rejected only later because `ConvertAggStateCast` cannot reach the `CombineCombinator` producer across `LogicalAggregate`. That is an incomplete integration rather than a consistently implemented exact-match contract. Also, casting the raw arguments is not a general workaround: an SQL type cast can retarget the subtype, but it normally cannot change a nullable expression into the target's non-nullable AggState metadata. Nullable-to-non-nullable targets can therefore remain impossible to satisfy through the suggested caller-side cast. A smaller acceptable fix would be to reject non-exact `_combine` coercions consistently at the explicit-cast/sink boundary, return an actionable analysis error, document this difference from `_state`, and add explicit CAST plus INSERT tests. Otherwise, please implement producer-aware coercion. Without either approach, I do not think the existing loose AggState cast contract and the proposed exact-match restriction are reconciled. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
