| // 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.rewrite.mvrewrite; |
| |
| import org.apache.doris.analysis.CaseExpr; |
| import org.apache.doris.analysis.CaseWhenClause; |
| import org.apache.doris.analysis.Expr; |
| import org.apache.doris.analysis.IntLiteral; |
| import org.apache.doris.analysis.IsNullPredicate; |
| import org.apache.doris.catalog.Type; |
| import org.apache.doris.common.AnalysisException; |
| |
| import com.google.common.collect.Lists; |
| |
| /** |
| * Rewrite count(k1) to sum(mv_count_k1) when MV Column exists. |
| * For example: |
| * Table: (k1 int ,k2 varchar) |
| * MV: (k1 int, mv_count_k2 bigint sum) |
| * mv_count_k1 = case when k2 is null then 0 else 1 |
| * Query: select k1, count(k2) from table group by k1 |
| * Rewritten query: select k1, sum(mv_count_k2) from table group by k1 |
| */ |
| public class CountFieldToSum { |
| |
| public static Expr slotToCaseWhen(Expr expr) throws AnalysisException { |
| return new CaseExpr(null, Lists.newArrayList(new CaseWhenClause( |
| new IsNullPredicate(expr, false), |
| new IntLiteral(0, Type.BIGINT))), new IntLiteral(1, Type.BIGINT)); |
| } |
| } |
