GitHub user HyukjinKwon opened a pull request: https://github.com/apache/spark/pull/16553
[SPARK-9435][SQL] Reuse function in Java UDF to correctly support expressions that require equality comparison ## What changes were proposed in this pull request? Currently, running the codes in Java ```java spark.udf().register("inc", new UDF1<Long, Long>() { @Override public Long call(Long i) { return i + 1; } }, DataTypes.LongType); spark.range(10).toDF("x").createOrReplaceTempView("tmp"); Row result = spark.sql("SELECT inc(x) FROM tmp GROUP BY inc(x)").head(); Assert.assertEquals(7, result.getLong(0)); ``` fails as below: ``` org.apache.spark.sql.AnalysisException: expression 'tmp.`x`' is neither present in the group by, nor is it an aggregate function. Add to group by or wrap in first() (or first_value) if you don't care which value you get.;; Aggregate [UDF(x#19L)], [UDF(x#19L) AS UDF(x)#23L] +- SubqueryAlias tmp, `tmp` +- Project [id#16L AS x#19L] +- Range (0, 10, step=1, splits=Some(8)) at org.apache.spark.sql.catalyst.analysis.CheckAnalysis$class.failAnalysis(CheckAnalysis.scala:40) at org.apache.spark.sql.catalyst.analysis.Analyzer.failAnalysis(Analyzer.scala:57) ``` The root cause is because we were creating the function every time when it needs to build as below: ```scala scala> def inc(i: Int) = i + 1 inc: (i: Int)Int scala> (inc(_: Int)).hashCode res15: Int = 1231799381 scala> (inc(_: Int)).hashCode res16: Int = 2109839984 scala> (inc(_: Int)) == (inc(_: Int)) res17: Boolean = false ``` This seems leading to the comparison failure between `ScalaUDF` created from Java UDF API, for example, in `Expression.semanticEquals`. In case of Scala one, it seems already fine. Both can be tested easily as below if any reviewer is comfortable with Scala: ```scala val df = Seq((1, 10), (2, 11), (3, 12)).toDF("x", "y") val javaUDF = new UDF1[Int, Int] { override def call(i: Int): Int = i + 1 } // spark.udf.register("inc", javaUDF, IntegerType) // Uncomment this for Java API // spark.udf.register("inc", (i: Int) => i + 1) // Uncomment this for Scala API df.createOrReplaceTempView("tmp") spark.sql("SELECT inc(y) FROM tmp GROUP BY inc(y)").show() ``` ## How was this patch tested? Unit test in `JavaUDFSuite.java`. You can merge this pull request into a Git repository by running: $ git pull https://github.com/HyukjinKwon/spark SPARK-9435 Alternatively you can review and apply these changes as the patch at: https://github.com/apache/spark/pull/16553.patch To close this pull request, make a commit to your master/trunk branch with (at least) the following in the commit message: This closes #16553 ---- commit 30ed14f38b5c38091d07d0e014a49e494aeb73cc Author: hyukjinkwon <gurwls...@gmail.com> Date: 2017-01-11T18:02:08Z Reuse function in Java UDF to support correctly expression equality comparison ---- --- If your project is set up for it, you can reply to this email and have your reply appear on GitHub as well. If your project does not have this feature enabled and wishes so, or if the feature is enabled but not working, please contact infrastructure at infrastruct...@apache.org or file a JIRA ticket with INFRA. --- --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org