Amend vector index queries

Author: nicktobey

enginetest/queries/vector_index_queries.go

@@ -25,32 +25,38 @@ var VectorIndexQueries = []ScriptTest{
 		SetUpScript: []string{
 			"create table vectors (id int primary key, v json);",
 			`insert into vectors values (1, '[3.0,4.0]'), (2, '[0.0,0.0]'), (3, '[1.0,-1.0]'), (4, '[-2.0,0.0]');`,
+			`create vector index v_idx on vectors(v);`,
 		},
 		Assertions: []ScriptTestAssertion{
 			{
-				Query: `create vector index v_idx on vectors(v);`,
+				Query: "show create table vectors",
 				Expected: []sql.Row{
-					{types.OkResult{RowsAffected: 0}},
+					{"vectors", "CREATE TABLE `vectors` (\n  `id` int NOT NULL,\n  `v` json,\n  PRIMARY KEY (`id`),\n  VECTOR KEY `v_idx` (`v`)\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_bin"},
 				},
 			},
 			{
-				Query: "show create table vectors",
+				Query: "select * from vectors order by VEC_DISTANCE('[0.0,0.0]', v) limit 4",
 				Expected: []sql.Row{
-					{"vectors", "CREATE TABLE `vectors` (\n  `id` int NOT NULL,\n  `v` json,\n  PRIMARY KEY (`id`),\n  VECTOR KEY `v_idx` (`v`)\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_bin"},
+					{2, types.MustJSON(`[0.0, 0.0]`)},
+					{3, types.MustJSON(`[1.0, -1.0]`)},
+					{4, types.MustJSON(`[-2.0, 0.0]`)},
+					{1, types.MustJSON(`[3.0, 4.0]`)},
 				},
+				ExpectedIndexes: []string{"v_idx"},
 			},
 			{
+				// Only queries with a limit can use a vector index.
 				Query: "select * from vectors order by VEC_DISTANCE('[0.0,0.0]', v)",
 				Expected: []sql.Row{
 					{2, types.MustJSON(`[0.0, 0.0]`)},
 					{3, types.MustJSON(`[1.0, -1.0]`)},
 					{4, types.MustJSON(`[-2.0, 0.0]`)},
 					{1, types.MustJSON(`[3.0, 4.0]`)},
 				},
-				ExpectedIndexes: []string{"v_idx"},
+				ExpectedIndexes: []string{""},
 			},
 			{
-				Query: "select * from vectors order by VEC_DISTANCE_L2_SQUARED('[-2.0,0.0]', v)",
+				Query: "select * from vectors order by VEC_DISTANCE_L2_SQUARED('[-2.0,0.0]', v) limit 4",
 				Expected: []sql.Row{
 					{4, types.MustJSON(`[-2.0, 0.0]`)},
 					{2, types.MustJSON(`[0.0, 0.0]`)},