sql: do not distribute queries with subqueries returning OIDs

If a subquery results in a DOid datum, the datum will get a type
annotation (because DOids are ambiguous) when serializing the
render expression involving the result of the subquery. As a
result, we might need to perform a cast on a remote node which
might fail, thus we prohibit the distribution of the main query.

Release justification: bug fix.

Release note: None

pkg/sql/distsql_physical_planner.go

@@ -273,6 +273,16 @@ func (v *distSQLExprCheckVisitor) VisitPre(expr tree.Expr) (recurse bool, newExp
 	case *tree.DOid:
 		v.err = newQueryNotSupportedError("OID expressions are not supported by distsql")
 		return false, expr
+	case *tree.Subquery:
+		if hasOidType(t.ResolvedType()) {
+			// If a subquery results in a DOid datum, the datum will get a type
+			// annotation (because DOids are ambiguous) when serializing the
+			// render expression involving the result of the subquery. As a
+			// result, we might need to perform a cast on a remote node which
+			// might fail, thus we prohibit the distribution of the main query.
+			v.err = newQueryNotSupportedError("OID expressions are not supported by distsql")
+			return false, expr
+		}
 	case *tree.CastExpr:
 		// TODO (rohany): I'm not sure why this CastExpr doesn't have a type
 		//  annotation at this stage of processing...
@@ -302,6 +312,23 @@ func (v *distSQLExprCheckVisitor) VisitPre(expr tree.Expr) (recurse bool, newExp
 
 func (v *distSQLExprCheckVisitor) VisitPost(expr tree.Expr) tree.Expr { return expr }
 
+// hasOidType returns whether t or its contents include an OID type.
+func hasOidType(t *types.T) bool {
+	switch t.Family() {
+	case types.OidFamily:
+		return true
+	case types.ArrayFamily:
+		return hasOidType(t.ArrayContents())
+	case types.TupleFamily:
+		for _, typ := range t.TupleContents() {
+			if hasOidType(typ) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
 // checkExpr verifies that an expression doesn't contain things that are not yet
 // supported by distSQL, like distSQL-blocklisted functions.
 func checkExpr(expr tree.Expr) error {

pkg/sql/logictest/testdata/logic_test/distsql_subquery

@@ -29,3 +29,24 @@ query T
 SELECT ARRAY(SELECT a FROM ab ORDER BY b)
 ----
 {1,2,1}
+
+# Regression tests for distributing a query which involves a subquery resulting
+# in an OID type (#86075).
+statement ok
+CREATE TABLE t86075 (k INT PRIMARY KEY, c REGPROCEDURE, a REGPROCEDURE[]);
+INSERT INTO t86075 VALUES (1, 1, ARRAY[1]);
+
+statement ok
+ALTER TABLE t86075 EXPERIMENTAL_RELOCATE VALUES (ARRAY[2], 1)
+
+statement ok
+SELECT (SELECT c FROM t86075) FROM t86075
+
+statement ok
+SELECT (SELECT a FROM t86075) FROM t86075
+
+statement ok
+SELECT (SELECT (c, c) FROM t86075) FROM t86075
+
+statement ok
+SELECT k FROM t86075 WHERE c = (SELECT c FROM t86075 LIMIT 1)

pkg/sql/logictest/testdata/logic_test/hash_join_dist

@@ -88,3 +88,37 @@ LEFT JOIN b AS b2 ON (a.id = b2.a_id AND b2.status = 2)
 WHERE (a.id IN ('3f90e30a-c87a-4017-b9a0-8f964b91c4af', '3adaf3da-0368-461a-8437-ee448724b78d', 'd0c13b06-5368-4522-8126-105b0a9513cd'))
 ORDER BY id DESC
 LIMIT 2;
+
+# Some tests with OID types in the equality columns.
+
+statement ok
+CREATE TABLE t86075 (k INT PRIMARY KEY, c REGPROCEDURE, a REGPROCEDURE[]);
+INSERT INTO t86075 VALUES (1, 1, ARRAY[1]), (2, 2, ARRAY[2]), (3, 3, ARRAY[3]);
+CREATE TABLE t86075_2 (k INT PRIMARY KEY, c REGPROCEDURE, a REGPROCEDURE[]);
+INSERT INTO t86075_2 VALUES (1, 1, ARRAY[1]), (2, 2, ARRAY[2]), (3, 3, ARRAY[3]);
+
+statement ok
+ALTER TABLE t86075 SPLIT AT VALUES (2), (3)
+
+statement ok
+ALTER TABLE t86075 SCATTER
+
+statement ok
+ALTER TABLE t86075_2 SPLIT AT VALUES (2), (3)
+
+statement ok
+ALTER TABLE t86075_2 SCATTER
+
+query I rowsort
+SELECT t1.k FROM t86075 AS t1, t86075_2 AS t2 WHERE t1.c = t2.c
+----
+1
+2
+3
+
+query I rowsort
+SELECT t1.k FROM t86075 AS t1, t86075_2 AS t2 WHERE t1.a = t2.a
+----
+1
+2
+3

pkg/sql/sem/tree/expr.go

@@ -950,6 +950,14 @@ type Subquery struct {
 	typeAnnotation
 }
 
+// ResolvedType implements the TypedExpr interface.
+func (node *Subquery) ResolvedType() *types.T {
+	if node.typ == nil {
+		return types.Any
+	}
+	return node.typ
+}
+
 // SetType forces the type annotation on the Subquery node.
 func (node *Subquery) SetType(t *types.T) {
 	node.typ = t