Github user gatorsmile commented on a diff in the pull request:
https://github.com/apache/spark/pull/23139#discussion_r236468395
--- Diff:
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/ReplaceNullWithFalseInPredicate.scala
---
@@ -0,0 +1,110 @@
+/*
+ * 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.optimizer
+
+import org.apache.spark.sql.catalyst.expressions.{And, ArrayExists,
ArrayFilter, CaseWhen, Expression, If}
+import org.apache.spark.sql.catalyst.expressions.{LambdaFunction, Literal,
MapFilter, Or}
+import org.apache.spark.sql.catalyst.expressions.Literal.FalseLiteral
+import org.apache.spark.sql.catalyst.plans.logical.{Filter, Join,
LogicalPlan}
+import org.apache.spark.sql.catalyst.rules.Rule
+import org.apache.spark.sql.types.BooleanType
+import org.apache.spark.util.Utils
+
+
+/**
+ * A rule that replaces `Literal(null, BooleanType)` with `FalseLiteral`,
if possible, in the search
+ * condition of the WHERE/HAVING/ON(JOIN) clauses, which contain an
implicit Boolean operator
+ * "(search condition) = TRUE". The replacement is only valid when
`Literal(null, BooleanType)` is
--- End diff --
This is based on the ANSI SQL. All these clauses have the implicit Boolean
operator "(search condition) = TRUE". That is why NULL and FALSE do not satisfy
the condition in these clauses
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
