## What changes were proposed in this pull request?
The tests added at https://github.com/apache/spark/pull/25069 seem flaky in some environments. See https://github.com/apache/spark/pull/25069#issuecomment-510338469
Python's string representation of floats can make the tests flaky. See https://docs.python.org/3/tutorial/floatingpoint.html.
I think it's just better to explicitly cast everywhere udf returns a float (or a double) to stay safe. (note that we're not targeting the Python <> Scala value conversions - there are inevitable differences between Python and Scala; therefore, other languages' UDFs cannot guarantee the same results between Python and Scala).
This PR proposes to cast cases to long, integer and decimal explicitly to make the test cases robust.
<details><summary>Diff comparing to 'pgSQL/aggregates_part1.sql'</summary>
<p>
```diff
diff --git a/sql/core/src/test/resources/sql-tests/results/pgSQL/aggregates_part1.sql.out b/sql/core/src/test/resources/sql-tests/results/udf/pgSQL/udf-aggregates_part1.sql.out
index 51ca1d55869..734634b7388 100644
--- a/sql/core/src/test/resources/sql-tests/results/pgSQL/aggregates_part1.sql.out
+++ b/sql/core/src/test/resources/sql-tests/results/udf/pgSQL/udf-aggregates_part1.sql.out
-3,23 +3,23
-- !query 0
-SELECT avg(four) AS avg_1 FROM onek
+SELECT CAST(avg(udf(four)) AS decimal(10,3)) AS avg_1 FROM onek
-- !query 0 schema
-struct<avg_1:double>
+struct<avg_1:decimal(10,3)>
-- !query 0 output
1.5
-- !query 1
-SELECT avg(a) AS avg_32 FROM aggtest WHERE a < 100
+SELECT CAST(udf(avg(a)) AS decimal(10,3)) AS avg_32 FROM aggtest WHERE a < 100
-- !query 1 schema
-struct<avg_32:double>
+struct<avg_32:decimal(10,3)>
-- !query 1 output
-32.666666666666664
+32.667
-- !query 2
-select CAST(avg(b) AS Decimal(10,3)) AS avg_107_943 FROM aggtest
+select CAST(avg(udf(b)) AS Decimal(10,3)) AS avg_107_943 FROM aggtest
-- !query 2 schema
struct<avg_107_943:decimal(10,3)>
-- !query 2 output
-27,39 +27,39 struct<avg_107_943:decimal(10,3)>
-- !query 3
-SELECT sum(four) AS sum_1500 FROM onek
+SELECT CAST(sum(udf(four)) AS int) AS sum_1500 FROM onek
-- !query 3 schema
-struct<sum_1500:bigint>
+struct<sum_1500:int>
-- !query 3 output
1500
-- !query 4
-SELECT sum(a) AS sum_198 FROM aggtest
+SELECT udf(sum(a)) AS sum_198 FROM aggtest
-- !query 4 schema
-struct<sum_198:bigint>
+struct<sum_198:string>
-- !query 4 output
198
-- !query 5
-SELECT sum(b) AS avg_431_773 FROM aggtest
+SELECT CAST(udf(udf(sum(b))) AS decimal(10,3)) AS avg_431_773 FROM aggtest
-- !query 5 schema
-struct<avg_431_773:double>
+struct<avg_431_773:decimal(10,3)>
-- !query 5 output
-431.77260909229517
+431.773
-- !query 6
-SELECT max(four) AS max_3 FROM onek
+SELECT udf(max(four)) AS max_3 FROM onek
-- !query 6 schema
-struct<max_3:int>
+struct<max_3:string>
-- !query 6 output
3
-- !query 7
-SELECT max(a) AS max_100 FROM aggtest
+SELECT max(CAST(udf(a) AS int)) AS max_100 FROM aggtest
-- !query 7 schema
struct<max_100:int>
-- !query 7 output
-67,245 +67,246 struct<max_100:int>
-- !query 8
-SELECT max(aggtest.b) AS max_324_78 FROM aggtest
+SELECT CAST(udf(udf(max(aggtest.b))) AS decimal(10,3)) AS max_324_78 FROM aggtest
-- !query 8 schema
-struct<max_324_78:float>
+struct<max_324_78:decimal(10,3)>
-- !query 8 output
324.78
-- !query 9
-SELECT stddev_pop(b) FROM aggtest
+SELECT CAST(stddev_pop(udf(b)) AS decimal(10,3)) FROM aggtest
-- !query 9 schema
-struct<stddev_pop(CAST(b AS DOUBLE)):double>
+struct<CAST(stddev_pop(CAST(udf(b) AS DOUBLE)) AS DECIMAL(10,3)):decimal(10,3)>
-- !query 9 output
-131.10703231895047
+131.107
-- !query 10
-SELECT stddev_samp(b) FROM aggtest
+SELECT CAST(udf(stddev_samp(b)) AS decimal(10,3)) FROM aggtest
-- !query 10 schema
-struct<stddev_samp(CAST(b AS DOUBLE)):double>
+struct<CAST(udf(stddev_samp(cast(b as double))) AS DECIMAL(10,3)):decimal(10,3)>
-- !query 10 output
-151.38936080399804
+151.389
-- !query 11
-SELECT var_pop(b) FROM aggtest
+SELECT CAST(var_pop(udf(b)) AS decimal(10,3)) FROM aggtest
-- !query 11 schema
-struct<var_pop(CAST(b AS DOUBLE)):double>
+struct<CAST(var_pop(CAST(udf(b) AS DOUBLE)) AS DECIMAL(10,3)):decimal(10,3)>
-- !query 11 output
-17189.053923482323
+17189.054
-- !query 12
-SELECT var_samp(b) FROM aggtest
+SELECT CAST(udf(var_samp(b)) AS decimal(10,3)) FROM aggtest
-- !query 12 schema
-struct<var_samp(CAST(b AS DOUBLE)):double>
+struct<CAST(udf(var_samp(cast(b as double))) AS DECIMAL(10,3)):decimal(10,3)>
-- !query 12 output
-22918.738564643096
+22918.739
-- !query 13
-SELECT stddev_pop(CAST(b AS Decimal(38,0))) FROM aggtest
+SELECT CAST(udf(stddev_pop(CAST(b AS Decimal(38,0)))) AS decimal(10,3)) FROM aggtest
-- !query 13 schema
-struct<stddev_pop(CAST(CAST(b AS DECIMAL(38,0)) AS DOUBLE)):double>
+struct<CAST(udf(stddev_pop(cast(cast(b as decimal(38,0)) as double))) AS DECIMAL(10,3)):decimal(10,3)>
-- !query 13 output
-131.18117242958306
+131.181
-- !query 14
-SELECT stddev_samp(CAST(b AS Decimal(38,0))) FROM aggtest
+SELECT CAST(stddev_samp(CAST(udf(b) AS Decimal(38,0))) AS decimal(10,3)) FROM aggtest
-- !query 14 schema
-struct<stddev_samp(CAST(CAST(b AS DECIMAL(38,0)) AS DOUBLE)):double>
+struct<CAST(stddev_samp(CAST(CAST(udf(b) AS DECIMAL(38,0)) AS DOUBLE)) AS DECIMAL(10,3)):decimal(10,3)>
-- !query 14 output
-151.47497042966097
+151.475
-- !query 15
-SELECT var_pop(CAST(b AS Decimal(38,0))) FROM aggtest
+SELECT CAST(udf(var_pop(CAST(b AS Decimal(38,0)))) AS decimal(10,3)) FROM aggtest
-- !query 15 schema
-struct<var_pop(CAST(CAST(b AS DECIMAL(38,0)) AS DOUBLE)):double>
+struct<CAST(udf(var_pop(cast(cast(b as decimal(38,0)) as double))) AS DECIMAL(10,3)):decimal(10,3)>
-- !query 15 output
17208.5
-- !query 16
-SELECT var_samp(CAST(b AS Decimal(38,0))) FROM aggtest
+SELECT CAST(var_samp(udf(CAST(b AS Decimal(38,0)))) AS decimal(10,3)) FROM aggtest
-- !query 16 schema
-struct<var_samp(CAST(CAST(b AS DECIMAL(38,0)) AS DOUBLE)):double>
+struct<CAST(var_samp(CAST(udf(cast(b as decimal(38,0))) AS DOUBLE)) AS DECIMAL(10,3)):decimal(10,3)>
-- !query 16 output
-22944.666666666668
+22944.667
-- !query 17
-SELECT var_pop(1.0), var_samp(2.0)
+SELECT CAST(udf(var_pop(1.0)) AS int), var_samp(udf(2.0))
-- !query 17 schema
-struct<var_pop(CAST(1.0 AS DOUBLE)):double,var_samp(CAST(2.0 AS DOUBLE)):double>
+struct<CAST(udf(var_pop(cast(1.0 as double))) AS INT):int,var_samp(CAST(udf(2.0) AS DOUBLE)):double>
-- !query 17 output
-0.0 NaN
+0 NaN
-- !query 18
-SELECT stddev_pop(CAST(3.0 AS Decimal(38,0))), stddev_samp(CAST(4.0 AS Decimal(38,0)))
+SELECT CAST(stddev_pop(udf(CAST(3.0 AS Decimal(38,0)))) AS int), stddev_samp(CAST(udf(4.0) AS Decimal(38,0)))
-- !query 18 schema
-struct<stddev_pop(CAST(CAST(3.0 AS DECIMAL(38,0)) AS DOUBLE)):double,stddev_samp(CAST(CAST(4.0 AS DECIMAL(38,0)) AS DOUBLE)):double>
+struct<CAST(stddev_pop(CAST(udf(cast(3.0 as decimal(38,0))) AS DOUBLE)) AS INT):int,stddev_samp(CAST(CAST(udf(4.0) AS DECIMAL(38,0)) AS DOUBLE)):double>
-- !query 18 output
-0.0 NaN
+0 NaN
-- !query 19
-select sum(CAST(null AS int)) from range(1,4)
+select sum(udf(CAST(null AS int))) from range(1,4)
-- !query 19 schema
-struct<sum(CAST(NULL AS INT)):bigint>
+struct<sum(CAST(udf(cast(null as int)) AS DOUBLE)):double>
-- !query 19 output
NULL
-- !query 20
-select sum(CAST(null AS long)) from range(1,4)
+select sum(udf(CAST(null AS long))) from range(1,4)
-- !query 20 schema
-struct<sum(CAST(NULL AS BIGINT)):bigint>
+struct<sum(CAST(udf(cast(null as bigint)) AS DOUBLE)):double>
-- !query 20 output
NULL
-- !query 21
-select sum(CAST(null AS Decimal(38,0))) from range(1,4)
+select sum(udf(CAST(null AS Decimal(38,0)))) from range(1,4)
-- !query 21 schema
-struct<sum(CAST(NULL AS DECIMAL(38,0))):decimal(38,0)>
+struct<sum(CAST(udf(cast(null as decimal(38,0))) AS DOUBLE)):double>
-- !query 21 output
NULL
-- !query 22
-select sum(CAST(null AS DOUBLE)) from range(1,4)
+select sum(udf(CAST(null AS DOUBLE))) from range(1,4)
-- !query 22 schema
-struct<sum(CAST(NULL AS DOUBLE)):double>
+struct<sum(CAST(udf(cast(null as double)) AS DOUBLE)):double>
-- !query 22 output
NULL
-- !query 23
-select avg(CAST(null AS int)) from range(1,4)
+select avg(udf(CAST(null AS int))) from range(1,4)
-- !query 23 schema
-struct<avg(CAST(NULL AS INT)):double>
+struct<avg(CAST(udf(cast(null as int)) AS DOUBLE)):double>
-- !query 23 output
NULL
-- !query 24
-select avg(CAST(null AS long)) from range(1,4)
+select avg(udf(CAST(null AS long))) from range(1,4)
-- !query 24 schema
-struct<avg(CAST(NULL AS BIGINT)):double>
+struct<avg(CAST(udf(cast(null as bigint)) AS DOUBLE)):double>
-- !query 24 output
NULL
-- !query 25
-select avg(CAST(null AS Decimal(38,0))) from range(1,4)
+select avg(udf(CAST(null AS Decimal(38,0)))) from range(1,4)
-- !query 25 schema
-struct<avg(CAST(NULL AS DECIMAL(38,0))):decimal(38,4)>
+struct<avg(CAST(udf(cast(null as decimal(38,0))) AS DOUBLE)):double>
-- !query 25 output
NULL
-- !query 26
-select avg(CAST(null AS DOUBLE)) from range(1,4)
+select avg(udf(CAST(null AS DOUBLE))) from range(1,4)
-- !query 26 schema
-struct<avg(CAST(NULL AS DOUBLE)):double>
+struct<avg(CAST(udf(cast(null as double)) AS DOUBLE)):double>
-- !query 26 output
NULL
-- !query 27
-select sum(CAST('NaN' AS DOUBLE)) from range(1,4)
+select sum(CAST(udf('NaN') AS DOUBLE)) from range(1,4)
-- !query 27 schema
-struct<sum(CAST(NaN AS DOUBLE)):double>
+struct<sum(CAST(udf(NaN) AS DOUBLE)):double>
-- !query 27 output
NaN
-- !query 28
-select avg(CAST('NaN' AS DOUBLE)) from range(1,4)
+select avg(CAST(udf('NaN') AS DOUBLE)) from range(1,4)
-- !query 28 schema
-struct<avg(CAST(NaN AS DOUBLE)):double>
+struct<avg(CAST(udf(NaN) AS DOUBLE)):double>
-- !query 28 output
NaN
-- !query 30
-SELECT avg(CAST(x AS DOUBLE)), var_pop(CAST(x AS DOUBLE))
+SELECT avg(CAST(udf(x) AS DOUBLE)), var_pop(CAST(udf(x) AS DOUBLE))
FROM (VALUES ('Infinity'), ('1')) v(x)
-- !query 30 schema
-struct<avg(CAST(x AS DOUBLE)):double,var_pop(CAST(x AS DOUBLE)):double>
+struct<avg(CAST(udf(x) AS DOUBLE)):double,var_pop(CAST(udf(x) AS DOUBLE)):double>
-- !query 30 output
Infinity NaN
-- !query 31
-SELECT avg(CAST(x AS DOUBLE)), var_pop(CAST(x AS DOUBLE))
+SELECT avg(CAST(udf(x) AS DOUBLE)), var_pop(CAST(udf(x) AS DOUBLE))
FROM (VALUES ('Infinity'), ('Infinity')) v(x)
-- !query 31 schema
-struct<avg(CAST(x AS DOUBLE)):double,var_pop(CAST(x AS DOUBLE)):double>
+struct<avg(CAST(udf(x) AS DOUBLE)):double,var_pop(CAST(udf(x) AS DOUBLE)):double>
-- !query 31 output
Infinity NaN
-- !query 32
-SELECT avg(CAST(x AS DOUBLE)), var_pop(CAST(x AS DOUBLE))
+SELECT avg(CAST(udf(x) AS DOUBLE)), var_pop(CAST(udf(x) AS DOUBLE))
FROM (VALUES ('-Infinity'), ('Infinity')) v(x)
-- !query 32 schema
-struct<avg(CAST(x AS DOUBLE)):double,var_pop(CAST(x AS DOUBLE)):double>
+struct<avg(CAST(udf(x) AS DOUBLE)):double,var_pop(CAST(udf(x) AS DOUBLE)):double>
-- !query 32 output
NaN NaN
-- !query 33
-SELECT avg(CAST(x AS DOUBLE)), var_pop(CAST(x AS DOUBLE))
+SELECT CAST(avg(udf(CAST(x AS DOUBLE))) AS int), CAST(udf(var_pop(CAST(x AS DOUBLE))) AS decimal(10,3))
FROM (VALUES (100000003), (100000004), (100000006), (100000007)) v(x)
-- !query 33 schema
-struct<avg(CAST(x AS DOUBLE)):double,var_pop(CAST(x AS DOUBLE)):double>
+struct<CAST(avg(CAST(udf(cast(x as double)) AS DOUBLE)) AS INT):int,CAST(udf(var_pop(cast(x as double))) AS DECIMAL(10,3)):decimal(10,3)>
-- !query 33 output
-1.00000005E8 2.5
+100000005 2.5
-- !query 34
-SELECT avg(CAST(x AS DOUBLE)), var_pop(CAST(x AS DOUBLE))
+SELECT CAST(avg(udf(CAST(x AS DOUBLE))) AS long), CAST(udf(var_pop(CAST(x AS DOUBLE))) AS decimal(10,3))
FROM (VALUES (7000000000005), (7000000000007)) v(x)
-- !query 34 schema
-struct<avg(CAST(x AS DOUBLE)):double,var_pop(CAST(x AS DOUBLE)):double>
+struct<CAST(avg(CAST(udf(cast(x as double)) AS DOUBLE)) AS BIGINT):bigint,CAST(udf(var_pop(cast(x as double))) AS DECIMAL(10,3)):decimal(10,3)>
-- !query 34 output
-7.000000000006E12 1.0
+7000000000006 1
-- !query 35
-SELECT covar_pop(b, a), covar_samp(b, a) FROM aggtest
+SELECT CAST(udf(covar_pop(b, udf(a))) AS decimal(10,3)), CAST(covar_samp(udf(b), a) as decimal(10,3)) FROM aggtest
-- !query 35 schema
-struct<covar_pop(CAST(b AS DOUBLE), CAST(a AS DOUBLE)):double,covar_samp(CAST(b AS DOUBLE), CAST(a AS DOUBLE)):double>
+struct<CAST(udf(covar_pop(cast(b as double), cast(udf(a) as double))) AS DECIMAL(10,3)):decimal(10,3),CAST(covar_samp(CAST(udf(b) AS DOUBLE), CAST(a AS DOUBLE)) AS DECIMAL(10,3)):decimal(10,3)>
-- !query 35 output
-653.6289553875104 871.5052738500139
+653.629 871.505
-- !query 36
-SELECT corr(b, a) FROM aggtest
+SELECT CAST(corr(b, udf(a)) AS decimal(10,3)) FROM aggtest
-- !query 36 schema
-struct<corr(CAST(b AS DOUBLE), CAST(a AS DOUBLE)):double>
+struct<CAST(corr(CAST(b AS DOUBLE), CAST(udf(a) AS DOUBLE)) AS DECIMAL(10,3)):decimal(10,3)>
-- !query 36 output
-0.1396345165178734
+0.14
-- !query 37
-SELECT count(four) AS cnt_1000 FROM onek
+SELECT count(udf(four)) AS cnt_1000 FROM onek
-- !query 37 schema
struct<cnt_1000:bigint>
-- !query 37 output
-313,18 +314,18 struct<cnt_1000:bigint>
-- !query 38
-SELECT count(DISTINCT four) AS cnt_4 FROM onek
+SELECT udf(count(DISTINCT four)) AS cnt_4 FROM onek
-- !query 38 schema
-struct<cnt_4:bigint>
+struct<cnt_4:string>
-- !query 38 output
4
-- !query 39
-select ten, count(*), sum(four) from onek
+select ten, udf(count(*)), CAST(sum(udf(four)) AS int) from onek
group by ten order by ten
-- !query 39 schema
-struct<ten:int,count(1):bigint,sum(four):bigint>
+struct<ten:int,udf(count(1)):string,CAST(sum(CAST(udf(four) AS DOUBLE)) AS INT):int>
-- !query 39 output
0 100 100
1 100 200
-339,10 +340,10 struct<ten:int,count(1):bigint,sum(four):bigint>
-- !query 40
-select ten, count(four), sum(DISTINCT four) from onek
+select ten, count(udf(four)), udf(sum(DISTINCT four)) from onek
group by ten order by ten
-- !query 40 schema
-struct<ten:int,count(four):bigint,sum(DISTINCT four):bigint>
+struct<ten:int,count(udf(four)):bigint,udf(sum(distinct cast(four as bigint))):string>
-- !query 40 output
0 100 2
1 100 4
-357,11 +358,11 struct<ten:int,count(four):bigint,sum(DISTINCT four):bigint>
-- !query 41
-select ten, sum(distinct four) from onek a
+select ten, udf(sum(distinct four)) from onek a
group by ten
-having exists (select 1 from onek b where sum(distinct a.four) = b.four)
+having exists (select 1 from onek b where udf(sum(distinct a.four)) = b.four)
-- !query 41 schema
-struct<ten:int,sum(DISTINCT four):bigint>
+struct<ten:int,udf(sum(distinct cast(four as bigint))):string>
-- !query 41 output
0 2
2 2
-374,23 +375,23 struct<ten:int,sum(DISTINCT four):bigint>
select ten, sum(distinct four) from onek a
group by ten
having exists (select 1 from onek b
- where sum(distinct a.four + b.four) = b.four)
+ where sum(distinct a.four + b.four) = udf(b.four))
-- !query 42 schema
struct<>
-- !query 42 output
org.apache.spark.sql.AnalysisException
Aggregate/Window/Generate expressions are not valid in where clause of the query.
-Expression in where clause: [(sum(DISTINCT CAST((outer() + b.`four`) AS BIGINT)) = CAST(b.`four` AS BIGINT))]
+Expression in where clause: [(sum(DISTINCT CAST((outer() + b.`four`) AS BIGINT)) = CAST(udf(four) AS BIGINT))]
Invalid expressions: [sum(DISTINCT CAST((outer() + b.`four`) AS BIGINT))];
-- !query 43
select
- (select max((select i.unique2 from tenk1 i where i.unique1 = o.unique1)))
+ (select udf(max((select i.unique2 from tenk1 i where i.unique1 = o.unique1))))
from tenk1 o
-- !query 43 schema
struct<>
-- !query 43 output
org.apache.spark.sql.AnalysisException
-cannot resolve '`o.unique1`' given input columns: [i.even, i.fivethous, i.four, i.hundred, i.odd, i.string4, i.stringu1, i.stringu2, i.ten, i.tenthous, i.thousand, i.twenty, i.two, i.twothousand, i.unique1, i.unique2]; line 2 pos 63
+cannot resolve '`o.unique1`' given input columns: [i.even, i.fivethous, i.four, i.hundred, i.odd, i.string4, i.stringu1, i.stringu2, i.ten, i.tenthous, i.thousand, i.twenty, i.two, i.twothousand, i.unique1, i.unique2]; line 2 pos 67
```
</p>
</details>
## How was this patch tested?
Manually tested in local.
Also, with JDK 11:
```
Using /.../jdk-11.0.3.jdk/Contents/Home as default JAVA_HOME.
Note, this will be overridden by -java-home if it is set.
[info] Loading project definition from /.../spark/project
[info] Updating {file:/.../spark/project/}spark-build...
...
[info] SQLQueryTestSuite:
...
[info] - udf/pgSQL/udf-aggregates_part1.sql - Scala UDF (17 seconds, 228 milliseconds)
[info] - udf/pgSQL/udf-aggregates_part1.sql - Regular Python UDF (36 seconds, 170 milliseconds)
[info] - udf/pgSQL/udf-aggregates_part1.sql - Scalar Pandas UDF (41 seconds, 132 milliseconds)
...
```
Closes#25110 from HyukjinKwon/SPARK-28270-1.
Authored-by: HyukjinKwon <gurwls223@apache.org>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
19bcce1533