Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
[SPARK-40963][SQL] Set nullable correctly in project created by `Extr…
…actGenerator` ### What changes were proposed in this pull request? When creating the project list for the new projection In `ExtractGenerator`, take into account whether the generator is outer when setting nullable on generator-related output attributes. ### Why are the changes needed? This PR fixes an issue that can produce either incorrect results or a `NullPointerException`. It's a bit of an obscure issue in that I am hard-pressed to reproduce without using a subquery that has a inline table. Example: ``` select c1, explode(c4) as c5 from ( select c1, array(c3) as c4 from ( select c1, explode_outer(c2) as c3 from values (1, array(1, 2)), (2, array(2, 3)), (3, null) as data(c1, c2) ) ); +---+---+ |c1 |c5 | +---+---+ |1 |1 | |1 |2 | |2 |2 | |2 |3 | |3 |0 | +---+---+ ``` In the last row, `c5` is 0, but should be `NULL`. Another example: ``` select c1, exists(c4, x -> x is null) as c5 from ( select c1, array(c3) as c4 from ( select c1, explode_outer(c2) as c3 from values (1, array(1, 2)), (2, array(2, 3)), (3, array()) as data(c1, c2) ) ); +---+-----+ |c1 |c5 | +---+-----+ |1 |false| |1 |false| |2 |false| |2 |false| |3 |false| +---+-----+ ``` In the last row, `false` should be `true`. In both cases, at the time `CreateArray(c3)` is instantiated, `c3`'s nullability is incorrect because the new projection created by `ExtractGenerator` uses `generatorOutput` from `explode_outer(c2)` as a projection list. `generatorOutput` doesn't take into account that `explode_outer(c2)` is an _outer_ explode, so the nullability setting is lost. `UpdateAttributeNullability` will eventually fix the nullable setting for attributes referring to `c3`, but it doesn't fix the `containsNull` setting for `c4` in `explode(c4)` (from the first example) or `exists(c4, x -> x is null)` (from the second example). This example fails with a `NullPointerException`: ``` select c1, inline_outer(c4) from ( select c1, array(c3) as c4 from ( select c1, explode_outer(c2) as c3 from values (1, array(named_struct('a', 1, 'b', 2))), (2, array(named_struct('a', 3, 'b', 4), named_struct('a', 5, 'b', 6))), (3, array()) as data(c1, c2) ) ); 22/10/30 17:34:42 ERROR Executor: Exception in task 1.0 in stage 8.0 (TID 14) java.lang.NullPointerException at org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIteratorForCodegenStage1.generate_doConsume_1$(Unknown Source) at org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIteratorForCodegenStage1.generate_doConsume_0$(Unknown Source) at org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIteratorForCodegenStage1.processNext(Unknown Source) at org.apache.spark.sql.execution.BufferedRowIterator.hasNext(BufferedRowIterator.java:43) at org.apache.spark.sql.execution.WholeStageCodegenExec$$anon$1.hasNext(WholeStageCodegenExec.scala:760) at org.apache.spark.sql.execution.SparkPlan.$anonfun$getByteArrayRdd$1(SparkPlan.scala:364) ``` ### Does this PR introduce _any_ user-facing change? No. ### How was this patch tested? New unit test. Closes apache#38440 from bersprockets/SPARK-40963. Authored-by: Bruce Robbins <bersprockets@gmail.com> Signed-off-by: Hyukjin Kwon <gurwls223@apache.org> (cherry picked from commit 90d3154) Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
- Loading branch information