coldataext: remove an allocation in production builds for arrays

This commit makes it so that we only perform assertions in the datum vec
in the test builds. In particular, this allows us to remove an
allocation for each array object being set (which happens in
`tree.DArray.ResolvedType` where we construct an array type on demand).
I was just looking at a heap profile where this allocation accounted for
7% of all allocations.

Release note: None

pkg/col/coldataext/BUILD.bazel

@@ -19,6 +19,7 @@ go_library(
         "//pkg/sql/sem/eval",
         "//pkg/sql/sem/tree",
         "//pkg/sql/types",
+        "//pkg/util/buildutil",
         "@com_github_cockroachdb_errors//:errors",
     ],
 )

pkg/col/coldataext/datum_vec.go

@@ -21,6 +21,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/sql/sem/eval"
 	"github.com/cockroachdb/cockroach/pkg/sql/sem/tree"
 	"github.com/cockroachdb/cockroach/pkg/sql/types"
+	"github.com/cockroachdb/cockroach/pkg/util/buildutil"
 	"github.com/cockroachdb/errors"
 )
 
@@ -90,7 +91,9 @@ func (dv *datumVec) Get(i int) coldata.Datum {
 // Set implements coldata.DatumVec interface.
 func (dv *datumVec) Set(i int, v coldata.Datum) {
 	datum := convertToDatum(v)
-	dv.assertValidDatum(datum)
+	if buildutil.CrdbTestBuild {
+		dv.assertValidDatum(datum)
+	}
 	dv.data[i] = datum
 }
 
@@ -106,21 +109,27 @@ func (dv *datumVec) Window(start, end int) coldata.DatumVec {
 // CopySlice implements coldata.DatumVec interface.
 func (dv *datumVec) CopySlice(src coldata.DatumVec, destIdx, srcStartIdx, srcEndIdx int) {
 	castSrc := src.(*datumVec)
-	dv.assertSameTypeFamily(castSrc.t)
+	if buildutil.CrdbTestBuild {
+		dv.assertSameTypeFamily(castSrc.t)
+	}
 	copy(dv.data[destIdx:], castSrc.data[srcStartIdx:srcEndIdx])
 }
 
 // AppendSlice implements coldata.DatumVec interface.
 func (dv *datumVec) AppendSlice(src coldata.DatumVec, destIdx, srcStartIdx, srcEndIdx int) {
 	castSrc := src.(*datumVec)
-	dv.assertSameTypeFamily(castSrc.t)
+	if buildutil.CrdbTestBuild {
+		dv.assertSameTypeFamily(castSrc.t)
+	}
 	dv.data = append(dv.data[:destIdx], castSrc.data[srcStartIdx:srcEndIdx]...)
 }
 
 // AppendVal implements coldata.DatumVec interface.
 func (dv *datumVec) AppendVal(v coldata.Datum) {
 	datum := convertToDatum(v)
-	dv.assertValidDatum(datum)
+	if buildutil.CrdbTestBuild {
+		dv.assertValidDatum(datum)
+	}
 	dv.data = append(dv.data, datum)
 }