spark CountStar 源码
spark CountStar 代码
文件路径：/sql/catalyst/src/main/java/org/apache/spark/sql/connector/expressions/aggregate/CountStar.java
/*
* 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.spark.sql.connector.expressions.aggregate;
import org.apache.spark.annotation.Evolving;
import org.apache.spark.sql.connector.expressions.Expression;
import org.apache.spark.sql.internal.connector.ExpressionWithToString;
/**
* An aggregate function that returns the number of rows in a group.
*
* @since 3.2.0
*/
@Evolving
public final class CountStar extends ExpressionWithToString implements AggregateFunc {
public CountStar() {
}
@Override
public Expression[] children() { return EMPTY_EXPRESSION; }
}
相关信息
相关文章
0
赞
热门推荐
-
2、 - 优质文章
-
3、 gate.io
-
7、 golang
-
9、 openharmony