spark AnyValue 源码
spark AnyValue 代码
文件路径：/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/aggregate/AnyValue.scala
/*
* 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.catalyst.expressions.aggregate
import org.apache.spark.sql.catalyst.expressions._
import org.apache.spark.sql.catalyst.trees.UnaryLike
import org.apache.spark.sql.types._
/**
* Returns the first value of `child` for a group of rows. If the first value of `child`
* is `null`, it returns `null` (respecting nulls). Even if [[AnyValue]] is used on an already
* sorted column, if we do partial aggregation and final aggregation (when mergeExpression
* is used) its result will not be deterministic (unless the input table is sorted and has
* a single partition, and we use a single reducer to do the aggregation.).
* Interchangeable with [[First]].
*/
@ExpressionDescription(
usage = """
_FUNC_(expr[, isIgnoreNull]) - Returns some value of `expr` for a group of rows.
If `isIgnoreNull` is true, returns only non-null values.""",
examples = """
Examples:
> SELECT _FUNC_(col) FROM VALUES (10), (5), (20) AS tab(col);
10
> SELECT _FUNC_(col) FROM VALUES (NULL), (5), (20) AS tab(col);
NULL
> SELECT _FUNC_(col, true) FROM VALUES (NULL), (5), (20) AS tab(col);
5
""",
note = """
The function is non-deterministic.
""",
group = "agg_funcs",
since = "3.4.0")
case class AnyValue(child: Expression, ignoreNulls: Boolean)
extends AggregateFunction with ExpectsInputTypes with RuntimeReplaceableAggregate
with UnaryLike[Expression] {
override lazy val replacement: Expression = First(child, ignoreNulls)
def this(child: Expression) = this(child, false)
def this(child: Expression, ignoreNullsExpr: Expression) = {
this(child, FirstLast.validateIgnoreNullExpr(ignoreNullsExpr, "any_value"))
}
override protected def withNewChildInternal(newChild: Expression): AnyValue =
copy(child = newChild)
override def inputTypes: Seq[AbstractDataType] = Seq(AnyDataType, BooleanType)
}
相关信息
相关文章
spark ApproxCountDistinctForIntervals 源码
0
赞
- 所属分类： 前端技术
- 本文标签：
热门推荐
-
2、 - 优质文章
-
3、 gate.io
-
8、 golang
-
9、 openharmony
-
10、 Vue中input框自动聚焦