planner: fix wrong index merge join plan for join key is not the pref…

…ix of index (#16894) (#17365)
pingcap · May 25, 2020 · 8ab4555 · 8ab4555
1 parent 49f2853
commit 8ab4555
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Showing 3 changed files with 24 additions and 2 deletions.
diff --git a/executor/index_lookup_join_test.go b/executor/index_lookup_join_test.go
@@ -197,3 +197,17 @@ func (s *testSuite5) TestIndexJoinMultiCondition(c *C) {
 	tk.MustExec("insert into t2 values (0,1), (0,2), (0,3)")
 	tk.MustQuery("select /*+ TIDB_INLJ(t1) */ count(*) from t1, t2 where t1.a = t2.a and t1.b < t2.b").Check(testkit.Rows("3"))
 }
+
+func (s *testSuite5) TestIssue16887(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists admin_roles, admin_role_has_permissions")
+	tk.MustExec("CREATE TABLE `admin_role_has_permissions` (`permission_id` bigint(20) unsigned NOT NULL, `role_id` bigint(20) unsigned NOT NULL, PRIMARY KEY (`permission_id`,`role_id`), KEY `admin_role_has_permissions_role_id_foreign` (`role_id`))")
+	tk.MustExec("CREATE TABLE `admin_roles` (`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(255) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL COMMENT '角色名称', `created_at` timestamp NULL DEFAULT NULL, `updated_at` timestamp NULL DEFAULT NULL, PRIMARY KEY (`id`))")
+	tk.MustExec("INSERT INTO `admin_roles` (`id`, `name`, `created_at`, `updated_at`) VALUES(1, 'admin','2020-04-27 02:40:03', '2020-04-27 02:40:03'),(2, 'developer','2020-04-27 02:40:03', '2020-04-27 02:40:03'),(3, 'analyst','2020-04-27 02:40:03', '2020-04-27 02:40:03'),(4, 'channel_admin','2020-04-27 02:40:03', '2020-04-27 02:40:03'),(5, 'test','2020-04-27 02:40:08', '2020-04-27 02:40:08')")
+	tk.MustExec("INSERT INTO `admin_role_has_permissions` (`permission_id`, `role_id`) VALUES(1, 1),(2, 1),(3, 1),(4, 1),(5, 1),(6, 1),(7, 1),(8, 1),(9, 1),(10, 1),(11, 1),(12, 1),(13, 1),(14, 1),(15, 1),(16, 1),(17, 1),(18, 1),(19, 1),(20, 1),(21, 1),(22, 1),(23, 1),(24, 1),(25, 1),(26, 1),(27, 1),(28, 1),(29, 1),(30, 1),(31, 1),(32, 1),(33, 1),(34, 1),(35, 1),(36, 1),(37, 1),(38, 1),(39, 1),(40, 1),(41, 1),(42, 1),(43, 1),(44, 1),(45, 1),(46, 1),(47, 1),(48, 1),(49, 1),(50, 1),(51, 1),(52, 1),(53, 1),(54, 1),(55, 1),(56, 1),(57, 1),(58, 1),(59, 1),(60, 1),(61, 1),(62, 1),(63, 1),(64, 1),(65, 1),(66, 1),(67, 1),(68, 1),(69, 1),(70, 1),(71, 1),(72, 1),(73, 1),(74, 1),(75, 1),(76, 1),(77, 1),(78, 1),(79, 1),(80, 1),(81, 1),(82, 1),(83, 1),(5, 4),(6, 4),(7, 4),(84, 5),(85, 5),(86, 5)")
+	rows := tk.MustQuery("SELECT /*+ inl_merge_join(admin_role_has_permissions) */ `admin_roles`.* FROM `admin_roles` INNER JOIN `admin_role_has_permissions` ON `admin_roles`.`id` = `admin_role_has_permissions`.`role_id` WHERE `admin_role_has_permissions`.`permission_id`\n IN (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67)").Rows()
+	c.Assert(len(rows), Equals, 70)
+	rows = tk.MustQuery("show warnings").Rows()
+	c.Assert(len(rows) > 0, Equals, true)
+}
diff --git a/planner/core/exhaust_physical_plans.go b/planner/core/exhaust_physical_plans.go
@@ -448,9 +448,17 @@ func (p *LogicalJoin) constructIndexMergeJoin(
 			keyOffMap[idxOff] = i
 		}
 		sort.Slice(keyOffMapList, func(i, j int) bool { return keyOffMapList[i] < keyOffMapList[j] })
+		keyIsIndexPrefix := true
 		for keyOff, idxOff := range keyOffMapList {
+			if keyOff != idxOff {
+				keyIsIndexPrefix = false
+				break
+			}
 			keyOff2KeyOffOrderByIdx[keyOffMap[idxOff]] = keyOff
 		}
+		if !keyIsIndexPrefix {
+			continue
+		}
 		// isOuterKeysPrefix means whether the outer join keys are the prefix of the prop items.
 		isOuterKeysPrefix := len(join.OuterJoinKeys) <= len(prop.Items)
 		compareFuncs := make([]expression.CompareFunc, 0, len(join.OuterJoinKeys))

diff --git a/planner/core/testdata/integration_suite_out.json b/planner/core/testdata/integration_suite_out.json
@@ -263,8 +263,8 @@
         "SQL": "desc select /*+ TIDB_INLJ(t2)*/ * from t1, t2 where t1.a = t2.a and t1.b = t2.a and t1.b = t2.b",
         "Plan": [
           "IndexJoin_12 12487.50 root  inner join, inner:TableReader_11, outer key:test.t1.a, test.t1.b, inner key:test.t2.a, test.t2.a, other cond:eq(test.t1.b, test.t2.b)",
-          "├─IndexReader_21(Build) 9990.00 root  index:IndexFullScan_20",
-          "│ └─IndexFullScan_20 9990.00 cop[tikv] table:t1, index:idx_t1_b(b) keep order:false, stats:pseudo",
+          "├─IndexReader_20(Build) 9990.00 root  index:IndexFullScan_19",
+          "│ └─IndexFullScan_19 9990.00 cop[tikv] table:t1, index:idx_t1_b(b) keep order:false, stats:pseudo",
           "└─TableReader_11(Probe) 1.00 root  data:Selection_10",
           "  └─Selection_10 1.00 cop[tikv]  not(isnull(test.t2.b))",
           "    └─TableRangeScan_9 1.00 cop[tikv] table:t2 range: decided by [test.t1.a test.t1.b], keep order:false, stats:pseudo"