builtins: fix aggregate functions for decimals

fixes cockroachdb#55944

Release note: none

pkg/sql/logictest/testdata/logic_test/aggregate

@@ -10,10 +10,12 @@ CREATE TABLE kv (
 )
 
 # Aggregate functions return NULL if there are no rows.
-query IIIIRRRRRRRRBBTIIR
-SELECT min(1), max(1), count(1), sum_int(1), avg(1), sum(1), stddev(1), stddev_samp(1), stddev_pop(1), var_samp(1), variance(1), var_pop(1), bool_and(true), bool_and(false), xor_agg(b'\x01'), bit_and(1), bit_or(1), corr(1, 1) FROM kv
+query IIIIRRRRRRRRBBTIIRR
+SELECT min(1), max(1), count(1), sum_int(1), avg(1), sum(1), stddev(1), stddev_samp(1), stddev_pop(1), var_samp(1),
+variance(1), var_pop(1), bool_and(true), bool_and(false), xor_agg(b'\x01'), bit_and(1), bit_or(1), corr(1, 1), sqrdiff(1)
+FROM kv
 ----
-NULL NULL 0 NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL
+NULL NULL 0 NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL
 
 # Regression test for #29695
 query T
@@ -42,10 +44,12 @@ SELECT min(i), avg(i), max(i), sum(i) FROM kv
 ----
 NULL NULL NULL NULL
 
-query IIIIRRRRRRBBTR
-SELECT min(v), max(v), count(v), sum_int(1), avg(v), sum(v), stddev(v), stddev_pop(v), variance(v), var_pop(v), bool_and(v = 1), bool_and(v = 1), xor_agg(s::bytes), corr(v,k) FROM kv
+query IIIIRRRRRRRBBTRR
+SELECT min(v), max(v), count(v), sum_int(1), avg(v), sum(v), stddev(v), stddev_pop(v), variance(v), var_pop(v), var_samp(v),
+bool_and(v = 1), bool_and(v = 1), xor_agg(s::bytes), corr(v,k), sqrdiff(v)
+FROM kv
 ----
-NULL NULL 0 NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL
+NULL NULL 0 NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL
 
 query T
 SELECT array_agg(v) FROM kv
@@ -63,10 +67,11 @@ SELECT jsonb_agg(v) FROM kv
 NULL
 
 # Aggregate functions triggers aggregation and computation when there is no source.
-query IIIIRRRRRRBBTR
-SELECT min(1), count(1), max(1), sum_int(1), avg(1)::float, sum(1), stddev_samp(1), stddev_pop(1), variance(1), var_pop(1), bool_and(true), bool_or(true), to_hex(xor_agg(b'\x01')), corr(1, 2)
+query IIIIRRRRRRRBBTRR
+SELECT min(1), count(1), max(1), sum_int(1), avg(1)::float, sum(1), stddev_samp(1), stddev_pop(1), variance(1),
+var_pop(1), var_samp(1), bool_and(true), bool_or(true), to_hex(xor_agg(b'\x01')), corr(1, 2), sqrdiff(1)
 ----
-1 1 1 1 1 1 NULL 0 NULL 0 true true 01 NULL
+1 1 1 1 1 1 NULL 0 NULL 0 NULL true true 01 NULL 0
 
 # Aggregate functions triggers aggregation and computation when there is no source.
 query T
@@ -162,10 +167,12 @@ INSERT INTO kv VALUES
 
 # Aggregate functions triggers aggregation and computation for every row even when applied to a constant.
 # NB: The XOR result is 00 because \x01 is XOR'd an even number of times.
-query IIIIRRRRRRBBT
-SELECT min(1), count(1), max(1), sum_int(1), avg(1)::float, sum(1), stddev(1), stddev_pop(1), variance(1)::float, var_pop(1)::float, bool_and(true), bool_or(true), to_hex(xor_agg(b'\x01')) FROM kv
+query IIIIRRRRRRRBBTR
+SELECT min(1), count(1), max(1), sum_int(1), avg(1)::float, sum(1), stddev(1), stddev_pop(1), variance(1)::float,
+var_pop(1)::float, var_samp(1)::float, bool_and(true), bool_or(true), to_hex(xor_agg(b'\x01')), sqrdiff(1)
+FROM kv
 ----
-1 6 1 6 1 6 0 0 0 0 true true 00
+1 6 1 6 1 6 0 0 0 0 0 true true 00 0
 
 # Aggregate functions triggers aggregation and computation for every row even when applied to a constant.
 query T
@@ -832,6 +839,40 @@ true
 statement ok
 DROP TABLE xyz
 
+# SQRDIFF
+
+statement ok
+DROP TABLE IF EXISTS ifd;
+CREATE TABLE ifd
+(
+ i int,
+ f float,
+ d decimal
+);
+INSERT INTO ifd (i, f, d)
+VALUES (1, 1.1, 1.1),
+ (2, 2.2, 2.2),
+ (5, 3.0, 3.0),
+ (10, 7.8, 7.8),
+ (11, 9.0, 9.0),
+ (18, 11.2, 11.2);
+
+query FRF
+select sqrdiff(i), round(sqrdiff(f), 13), sqrdiff(d)
+from ifd
+----
+206.8333333333333333333334 86.2483333333333 86.24833333333333333333333
+
+query FRF
+SELECT sqrdiff(i), round(sqrdiff(f), 2), sqrdiff(d)
+FROM ifd
+where i < 10
+----
+8.666666666666666666666666 1.82 1.82
+
+statement ok
+DROP TABLE IF EXISTS sqrdiff
+
 # Numerical stability test for VARIANCE/STDDEV.
 # See https://www.johndcook.com/blog/2008/09/28/theoretical-explanation-for-numerical-results.
 # Avoid using random() since we do not have the deterministic option to specify a pseudo-random seed yet.
@@ -2817,3 +2858,40 @@ query FI
 SELECT corr(DISTINCT y, x), count(DISTINCT y) FROM t55776
 ----
 0.522232967867094 3
+
+# Regression test for window aggregate functions for decimals reuse the results
+# from the previous iterations (#55944).
+statement ok
+CREATE TABLE t55944 (x decimal);
+INSERT INTO t55944 (x)
+VALUES (1.0),
+ (20.0),
+ (25.0),
+ (41.0),
+ (55.5),
+ (60.9),
+ (72.0),
+ (88.0),
+ (88.0),
+ (89.0);
+
+query RFFFFF
+SELECT x,
+ sqrdiff(x) OVER (ORDER BY x) as sqrdiff,
+ var_pop(x) OVER (ORDER BY x) as var_pop,
+ var_samp(x) OVER (ORDER BY x) as var_samp,
+ stddev_pop(x) OVER (ORDER BY x) as stddev_pop,
+ stddev_samp(x) OVER (ORDER BY x) as stddev_samp
+FROM t55944
+ORDER BY x
+----
+1.0 0 0 NULL 0 NULL
+20.0 180.5 90.25 180.5 9.5 13.435028842544402964
+25.0 320.6666666666666666666667 106.88888888888888889 160.33333333333333333 10.338708279513881752 12.662279942148385993
+41.0 814.7500000000000000000001 203.6875 271.58333333333333333 14.271912976192084391 16.479785597310825856
+55.5 1726 345.2 431.5 18.579558659989746915 20.772578077840988103
+60.9 2600.8 433.46666666666666667 520.16 20.819862311424316109 22.807016464237491316
+72.0 3845.037142857142857142857 549.29102040816326531 640.83952380952380952 23.436958429117103874 25.314808389745394427
+88.0 7527.842222222222222222222 836.42691358024691358 940.98027777777777778 28.921046204801217626 30.675401835636607970
+88.0 7527.842222222222222222222 836.42691358024691358 940.98027777777777778 28.921046204801217626 30.675401835636607970
+89.0 8885.844 888.5844 987.316 29.809132828715430446 31.421584937746218024

pkg/sql/sem/builtins/aggregate_builtins.go

@@ -2575,7 +2575,8 @@ func (a *decimalSqrDiffAggregate) Result() (tree.Datum, error) {
  if a.count.Cmp(decimalOne) < 0 {
  return tree.DNull, nil
  }
- dd := &tree.DDecimal{Decimal: a.sqrDiff}
+ dd := &tree.DDecimal{}
+ dd.Set(&a.sqrDiff)
  // Remove trailing zeros. Depending on the order in which the input
  // is processed, some number of trailing zeros could be added to the
  // output. Remove them so that the results are the same regardless of order.

pkg/sql/sem/builtins/aggregate_builtins_test.go

@@ -256,6 +256,21 @@ func TestVarianceDecimalResultDeepCopy(t *testing.T) {
  testAggregateResultDeepCopy(t, newDecimalVarianceAggregate, makeDecimalTestDatum(10))
 }
 
+func TestSqrDiffIntResultDeepCopy(t *testing.T) {
+ defer leaktest.AfterTest(t)()
+ testAggregateResultDeepCopy(t, newIntSqrDiffAggregate, makeIntTestDatum(10))
+}
+
+func TestSqrDiffFloatResultDeepCopy(t *testing.T) {
+ defer leaktest.AfterTest(t)()
+ testAggregateResultDeepCopy(t, newFloatSqrDiffAggregate, makeFloatTestDatum(10))
+}
+
+func TestSqrDiffDecimalResultDeepCopy(t *testing.T) {
+ defer leaktest.AfterTest(t)()
+ testAggregateResultDeepCopy(t, newDecimalSqrDiffAggregate, makeDecimalTestDatum(10))
+}
+
 func TestVarPopIntResultDeepCopy(t *testing.T) {
  defer leaktest.AfterTest(t)()
  testAggregateResultDeepCopy(t, newIntVarPopAggregate, makeIntTestDatum(10))
@@ -666,6 +681,30 @@ func BenchmarkVarianceAggregateDecimal(b *testing.B) {
  }
 }
 
+func BenchmarkSqrDiffAggregateInt(b *testing.B) {
+ for _, count := range []int{1000} {
+ b.Run(fmt.Sprintf("count=%d", count), func(b *testing.B) {
+ runBenchmarkAggregate(b, newIntSqrDiffAggregate, makeIntTestDatum(count))
+ })
+ }
+}
+
+func BenchmarkSqrDiffAggregateFloat(b *testing.B) {
+ for _, count := range []int{1000} {
+ b.Run(fmt.Sprintf("count=%d", count), func(b *testing.B) {
+ runBenchmarkAggregate(b, newFloatSqrDiffAggregate, makeFloatTestDatum(count))
+ })
+ }
+}
+
+func BenchmarkSqrDiffAggregateDecimal(b *testing.B) {
+ for _, count := range []int{1000} {
+ b.Run(fmt.Sprintf("count=%d", count), func(b *testing.B) {
+ runBenchmarkAggregate(b, newDecimalSqrDiffAggregate, makeDecimalTestDatum(count))
+ })
+ }
+}
+
 func BenchmarkVarPopAggregateInt(b *testing.B) {
  for _, count := range []int{1000} {
  b.Run(fmt.Sprintf("count=%d", count), func(b *testing.B) {