sql: support array_agg with arrays as inputs

This commit extends `array_agg` aggregate function to support arrays as
their input. The result of such aggregation is a nested array, and the
existing implementation simply works for that case.

The main complication of this change is that we currently don't support
multidimensional arrays in all cases, so previously we would disallow it
in a few places (like when creating a command result with a nested array
type). This commit had to remove that limitation since it was too broad.
There are still things that we don't support (e.g. in CREATE TABLE
context, or when the nested array needs to be serialized (we don't have
value encoding for it)), so in those cases we will keep on returning
errors.

Release note (sql change): `array_agg` aggregate function can now
support arrays as the input. Note, however, that CockroachDB still
doesn't have full support of nested arrays (that is tracked by #32552).

docs/generated/sql/aggregates.md

@@ -3,52 +3,100 @@
 <tbody>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="bool.html">bool</a>) &rarr; <a href="bool.html">bool</a>[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="bool.html">bool</a>[]) &rarr; <a href="bool.html">bool</a>[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="bytes.html">bytes</a>) &rarr; <a href="bytes.html">bytes</a>[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="bytes.html">bytes</a>[]) &rarr; <a href="bytes.html">bytes</a>[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="date.html">date</a>) &rarr; <a href="date.html">date</a>[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="date.html">date</a>[]) &rarr; <a href="date.html">date</a>[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="decimal.html">decimal</a>) &rarr; <a href="decimal.html">decimal</a>[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="decimal.html">decimal</a>[]) &rarr; <a href="decimal.html">decimal</a>[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="float.html">float</a>) &rarr; <a href="float.html">float</a>[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="float.html">float</a>[]) &rarr; <a href="float.html">float</a>[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="inet.html">inet</a>) &rarr; <a href="inet.html">inet</a>[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="inet.html">inet</a>[]) &rarr; <a href="inet.html">inet</a>[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="int.html">int</a>) &rarr; <a href="int.html">int</a>[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="int.html">int</a>[]) &rarr; <a href="int.html">int</a>[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="interval.html">interval</a>) &rarr; <a href="interval.html">interval</a>[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="interval.html">interval</a>[]) &rarr; <a href="interval.html">interval</a>[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="string.html">string</a>) &rarr; <a href="string.html">string</a>[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="string.html">string</a>[]) &rarr; <a href="string.html">string</a>[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="time.html">time</a>) &rarr; <a href="time.html">time</a>[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="time.html">time</a>[]) &rarr; <a href="time.html">time</a>[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="timestamp.html">timestamp</a>) &rarr; <a href="timestamp.html">timestamp</a>[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="timestamp.html">timestamp</a>[]) &rarr; <a href="timestamp.html">timestamp</a>[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="timestamp.html">timestamptz</a>) &rarr; <a href="timestamp.html">timestamptz</a>[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="timestamp.html">timestamptz</a>[]) &rarr; <a href="timestamp.html">timestamptz</a>[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="uuid.html">uuid</a>) &rarr; <a href="uuid.html">uuid</a>[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: <a href="uuid.html">uuid</a>[]) &rarr; <a href="uuid.html">uuid</a>[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: anyenum) &rarr; anyenum[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: anyenum[]) &rarr; anyenum[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: box2d) &rarr; box2d[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: box2d[]) &rarr; box2d[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: geography) &rarr; geography[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: geography[]) &rarr; geography[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: geometry) &rarr; geometry[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: geometry[]) &rarr; geometry[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: jsonb) &rarr; jsonb[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: jsonb[]) &rarr; jsonb[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: oid) &rarr; oid[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: oid[]) &rarr; oid[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: pg_lsn) &rarr; pg_lsn[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: pg_lsn[]) &rarr; pg_lsn[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: refcursor) &rarr; refcursor[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: refcursor[]) &rarr; refcursor[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: timetz) &rarr; timetz[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: timetz[]) &rarr; timetz[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: tuple) &rarr; tuple[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: tuple[]) &rarr; tuple[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_agg"></a><code>array_agg(arg1: varbit) &rarr; varbit[]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
 </span></td><td>Immutable</td></tr>
+<tr><td><a name="array_agg"></a><code>array_agg(arg1: varbit[]) &rarr; varbit[][]</code></td><td><span class="funcdesc"><p>Aggregates the selected values into an array.</p>
+</span></td><td>Immutable</td></tr>
 <tr><td><a name="array_cat_agg"></a><code>array_cat_agg(arg1: <a href="bool.html">bool</a>[]) &rarr; <a href="bool.html">bool</a>[]</code></td><td><span class="funcdesc"><p>Unnests the selected arrays into elements that are then aggregated into a single array.</p>
 </span></td><td>Immutable</td></tr>
 <tr><td><a name="array_cat_agg"></a><code>array_cat_agg(arg1: <a href="bytes.html">bytes</a>[]) &rarr; <a href="bytes.html">bytes</a>[]</code></td><td><span class="funcdesc"><p>Unnests the selected arrays into elements that are then aggregated into a single array.</p>

pkg/sql/exec_util.go

@@ -109,7 +109,6 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/upgrade/upgradebase"
 	"github.com/cockroachdb/cockroach/pkg/util/bitarray"
 	"github.com/cockroachdb/cockroach/pkg/util/duration"
-	"github.com/cockroachdb/cockroach/pkg/util/errorutil/unimplemented"
 	"github.com/cockroachdb/cockroach/pkg/util/hlc"
 	"github.com/cockroachdb/cockroach/pkg/util/log"
 	"github.com/cockroachdb/cockroach/pkg/util/metric"
@@ -2024,15 +2023,10 @@ func checkResultType(typ *types.T) error {
 	case types.EnumFamily:
 	case types.VoidFamily:
 	case types.ArrayFamily:
-		if typ.ArrayContents().Family() == types.ArrayFamily {
-			// Technically we could probably return arrays of arrays to a
-			// client (the encoding exists) but we don't want to give
-			// mixed signals -- that nested arrays appear to be supported
-			// in this case, and not in other cases (eg. CREATE). So we
-			// reject them in every case instead.
-			return unimplemented.NewWithIssueDetail(32552,
-				"result", "arrays cannot have arrays as element type")
-		}
+		// Note that we support multidimensional arrays in some cases (e.g.
+		// array_agg with arrays as inputs) but not in others (e.g. CREATE).
+		// Here we allow them in all cases and rely on each unsupported place to
+		// have the check.
 	case types.AnyFamily:
 		// Placeholder case.
 		return errors.Errorf("could not determine data type of %s", typ)

pkg/sql/logictest/testdata/logic_test/aggregate

@@ -3982,3 +3982,12 @@ SELECT array_cat_agg(
 )
 ----
 {(4.166442344843677e+17),(),(-0.12116245180368423)}
+
+statement ok
+CREATE TABLE __test_array_agg(a TEXT PRIMARY KEY, b TEXT, c TEXT);
+INSERT INTO __test_array_agg VALUES ('a', 'b', 'c'), ('aa', 'bb', 'cc'), ('aaa', 'bbb', 'ccc');
+
+query T
+SELECT array_agg(array[a, b, c]) FROM __test_array_agg;
+----
+{"{a,b,c}","{aa,bb,cc}","{aaa,bbb,ccc}"}

pkg/sql/logictest/testdata/logic_test/array

@@ -118,20 +118,23 @@ SELECT ARRAY(VALUES (1),(2),(1))
 ----
 {1,2,1}
 
-statement error arrays cannot have arrays as element type
+# This query works in local config but can fail in distributed config since the
+# support for nested arrays is incomplete.
+onlyif config local
+query T
 SELECT ARRAY(VALUES (ARRAY[1]))
+----
+{"{1}"}
 
 query T
 SELECT ARRAY(VALUES ('a'),('b'),('c'))
 ----
 {a,b,c}
 
-
-# TODO(justin): uncomment when #32715 is fixed.
-# query T
-# SELECT ARRAY(SELECT (1,2))
-# ----
-# {"(1,2)"}
+query T
+SELECT ARRAY(SELECT (1,2))
+----
+{"(1,2)"}
 
 query error subquery must return only one column, found 2
 SELECT ARRAY(SELECT 1, 2)
@@ -443,10 +446,13 @@ DROP TABLE boundedtable
 statement error .*unimplemented.*\nHINT.*\n.*32552
 CREATE TABLE badtable (b INT[][])
 
-# Nested arrays should be disallowed
-
-query error unimplemented: arrays cannot have arrays as element type.*\nHINT.*\n.*32552
+# This query works in local config but can fail in distributed config since the
+# support for nested arrays is incomplete.
+onlyif config local
+query T
 SELECT ARRAY[ARRAY[1,2,3]]
+----
+{"{1,2,3}"}
 
 # The postgres-compat aliases should be disallowed.
 # INT2VECTOR is deprecated in Postgres.

pkg/sql/opt/exec/execbuilder/testdata/subquery_correlated

@@ -11,8 +11,6 @@ statement ok
 CREATE TABLE c (c_id INT PRIMARY KEY, bill TEXT);
 CREATE TABLE o (o_id INT PRIMARY KEY, c_id INT, ship TEXT);
 
-# We can't decorrelate cases which don't use a scalar type in the
-# ARRAY(...) operator.
 query T
 EXPLAIN SELECT
   c_id,

pkg/sql/opt/memo/typing.go

@@ -109,19 +109,6 @@ func BinaryAllowsNullArgs(op opt.Operator, leftType, rightType *types.T) bool {
 // functions without importing the builtins package.
 var GetBuiltinProperties func(name string) (*tree.FunctionProperties, []tree.Overload)
 
-// AggregateOverloadExists returns whether or not the given operator has a
-// unary overload which takes the given type as input.
-func AggregateOverloadExists(agg opt.Operator, typ *types.T) bool {
-	name := opt.AggregateOpReverseMap[agg]
-	_, overloads := GetBuiltinProperties(name)
-	for _, o := range overloads {
-		if o.Types.MatchAt(typ, 0) {
-			return true
-		}
-	}
-	return false
-}
-
 // FindFunction returns the function properties and overload of the function
 // with the given name and argument types matching the children of the given
 // input.

pkg/sql/opt/optbuilder/scalar.go

@@ -146,15 +146,7 @@ func (b *Builder) buildScalar(
 		s := t.Subquery.(*subquery)
 
 		inCol := s.cols[0].id
-
-		// This looks kind of arbitrary and strange, because it is:
-		// We cannot array_agg over some types, but we can only decorrelate via array_agg.
-		// Thus, we reject a query that is correlated and over a type that we can't array_agg.
 		typ := b.factory.Metadata().ColumnMeta(inCol).Type
-		if !s.outerCols.Empty() && !memo.AggregateOverloadExists(opt.ArrayAggOp, typ) {
-			panic(unimplementedWithIssueDetailf(35710, "", "can't execute a correlated ARRAY(...) over %s", typ))
-		}
-
 		if err := types.CheckArrayElementType(typ); err != nil {
 			panic(err)
 		}

pkg/sql/opt/optbuilder/testdata/aggregate

@@ -208,29 +208,53 @@ build
 SELECT array_agg(NULL)
 ----
 error (42725): ambiguous call: array_agg(unknown), candidates are:
+array_agg(bool[]) -> bool[][]
 array_agg(box2d) -> box2d[]
+array_agg(box2d[]) -> box2d[][]
 array_agg(int) -> int[]
+array_agg(int[]) -> int[][]
 array_agg(float) -> float[]
+array_agg(float[]) -> float[][]
 array_agg(decimal) -> decimal[]
+array_agg(decimal[]) -> decimal[][]
 array_agg(date) -> date[]
+array_agg(date[]) -> date[][]
 array_agg(timestamp) -> timestamp[]
+array_agg(timestamp[]) -> timestamp[][]
 array_agg(interval) -> interval[]
+array_agg(interval[]) -> interval[][]
 array_agg(geography) -> geography[]
+array_agg(geography[]) -> geography[][]
 array_agg(geometry) -> geometry[]
+array_agg(geometry[]) -> geometry[][]
 array_agg(string) -> string[]
+array_agg(string[]) -> string[][]
 array_agg(bytes) -> bytes[]
+array_agg(bytes[]) -> bytes[][]
 array_agg(timestamptz) -> timestamptz[]
+array_agg(timestamptz[]) -> timestamptz[][]
 array_agg(oid) -> oid[]
+array_agg(oid[]) -> oid[][]
 array_agg(uuid) -> uuid[]
+array_agg(uuid[]) -> uuid[][]
 array_agg(inet) -> inet[]
+array_agg(inet[]) -> inet[][]
 array_agg(pg_lsn) -> pg_lsn[]
+array_agg(pg_lsn[]) -> pg_lsn[][]
 array_agg(refcursor) -> refcursor[]
+array_agg(refcursor[]) -> refcursor[][]
 array_agg(time) -> time[]
+array_agg(time[]) -> time[][]
 array_agg(timetz) -> timetz[]
+array_agg(timetz[]) -> timetz[][]
 array_agg(jsonb) -> jsonb[]
+array_agg(jsonb[]) -> jsonb[][]
 array_agg(varbit) -> varbit[]
+array_agg(varbit[]) -> varbit[][]
 array_agg(anyenum) -> anyenum[]
+array_agg(anyenum[]) -> anyenum[][]
 array_agg(tuple) -> tuple[]
+array_agg(tuple[]) -> tuple[][]
 array_agg(bool) -> bool[]
 
 # With an explicit cast, this works as expected.

pkg/sql/opt/optbuilder/testdata/scalar

@@ -1279,7 +1279,21 @@ project
 build
 SELECT ARRAY(SELECT y FROM u ORDER BY x) FROM v
 ----
-error (0A000): unimplemented: can't execute a correlated ARRAY(...) over int[]
+project
+ ├── columns: array:10
+ ├── scan v
+ │    └── columns: v.y:1 v.rowid:2!null v.crdb_internal_mvcc_timestamp:3 v.tableoid:4
+ └── projections
+      └── array-flatten col=9 [as=array:10]
+           └── sort
+                ├── columns: y:9  [hidden: x:5]
+                ├── ordering: +5
+                └── project
+                     ├── columns: y:9 x:5
+                     ├── scan u
+                     │    └── columns: x:5 u.rowid:6!null u.crdb_internal_mvcc_timestamp:7 u.tableoid:8
+                     └── projections
+                          └── v.y:1 [as=y:9]
 
 build-scalar
 ISERROR(1/0)

pkg/sql/rowenc/valueside/BUILD.bazel

@@ -22,6 +22,7 @@ go_library(
         "//pkg/sql/sem/tree",
         "//pkg/sql/types",
         "//pkg/util/encoding",
+        "//pkg/util/errorutil/unimplemented",
         "//pkg/util/ipaddr",
         "//pkg/util/json",
         "//pkg/util/timeutil/pgdate",

pkg/sql/rowenc/valueside/array.go

@@ -14,6 +14,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/sql/sem/tree"
 	"github.com/cockroachdb/cockroach/pkg/sql/types"
 	"github.com/cockroachdb/cockroach/pkg/util/encoding"
+	"github.com/cockroachdb/cockroach/pkg/util/errorutil/unimplemented"
 	"github.com/cockroachdb/cockroach/pkg/util/json"
 	"github.com/cockroachdb/cockroach/pkg/util/tsearch"
 	"github.com/cockroachdb/errors"
@@ -237,6 +238,8 @@ func DatumTypeToArrayElementEncodingType(t *types.T) (encoding.Type, error) {
 		return encoding.JSON, nil
 	case types.TupleFamily:
 		return encoding.Tuple, nil
+	case types.ArrayFamily:
+		return 0, unimplemented.NewWithIssueDetail(32552, "", "nested arrays are not fully supported")
 	default:
 		return 0, errors.AssertionFailedf("no known encoding type for %s", t.Family().Name())
 	}