spark-instrumented-optimizer/sql/catalyst
fqaiser94@gmail.com 3f1e56d4ca [SPARK-32641][SQL] withField + getField should return null if original struct was null
### What changes were proposed in this pull request?

There is a bug in the way the optimizer rule in `SimplifyExtractValueOps` is currently written in master branch which yields incorrect results in scenarios like the following:
```
sql("SELECT CAST(NULL AS struct<a:int,b:int>) struct_col")
.select($"struct_col".withField("d", lit(4)).getField("d").as("d"))

// currently returns this:
+---+
|d  |
+---+
|4  |
+---+

// when in fact it should return this:
+----+
|d   |
+----+
|null|
+----+
```
The changes in this PR will fix this bug.

### Why are the changes needed?

To fix the aforementioned bug. Optimizer rules should improve the performance of the  query but yield exactly the same results.

### Does this PR introduce _any_ user-facing change?

Yes, this bug will no longer occur.
That said, this isn't something to be concerned about as this bug was introduced in Spark 3.1 and Spark 3.1 has yet to be released.

### How was this patch tested?

Unit tests were added. Jenkins must pass them.

Closes #29522 from fqaiser94/SPARK-32641.

Authored-by: fqaiser94@gmail.com <fqaiser94@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
2020-08-25 04:59:37 +00:00
..
benchmarks [SPARK-30413][SQL] Avoid WrappedArray roundtrip in GenericArrayData constructor, plus related optimization in ParquetMapConverter 2020-01-19 19:12:19 -08:00
src [SPARK-32641][SQL] withField + getField should return null if original struct was null 2020-08-25 04:59:37 +00:00
pom.xml [SPARK-30950][BUILD] Setting version to 3.1.0-SNAPSHOT 2020-02-25 19:44:31 -08:00