PRE_SPLIT_REGIONS doesn't work after TRUNCATE PARTITION operation

[zhenemola]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

CREATE TABLE `tt` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  PRIMARY KEY (`id`) /*T![clustered_index] NONCLUSTERED */
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin /*T! SHARD_ROW_ID_BITS=4 PRE_SPLIT_REGIONS=3 */
PARTITION BY RANGE (`id`)
(PARTITION `p1` VALUES LESS THAN (10),
 PARTITION `p2` VALUES LESS THAN (20),
 PARTITION `p3` VALUES LESS THAN (MAXVALUE))

MySQL [test]> show table tt regions;
+-----------+-----------------------------+-----------------------------+-----------+-----------------+-----------------------------------+------------+---------------+------------+----------------------+------------------+
| REGION_ID | START_KEY                   | END_KEY                     | LEADER_ID | LEADER_STORE_ID | PEERS                             | SCATTERING | WRITTEN_BYTES | READ_BYTES | APPROXIMATE_SIZE(MB) | APPROXIMATE_KEYS |
+-----------+-----------------------------+-----------------------------+-----------+-----------------+-----------------------------------+------------+---------------+------------+----------------------+------------------+
|     19312 | t_263_                      | t_263_r_1152921504606846976 |     19313 |              15 | 19313, 19314, 19315, 19316, 19317 |          0 |             0 |          0 |                    1 |                0 |
|     19318 | t_263_r_1152921504606846976 | t_263_r_2305843009213693952 |     19319 |              15 | 19319, 19320, 19321, 19322, 19323 |          0 |             0 |          0 |                    1 |                0 |
|     19324 | t_263_r_2305843009213693952 | t_263_r_3458764513820540928 |     19325 |              15 | 19325, 19326, 19327, 19328, 19329 |          0 |             0 |          0 |                    1 |                0 |
|     19330 | t_263_r_3458764513820540928 | t_263_r_4611686018427387904 |     19331 |              15 | 19331, 19332, 19333, 19334, 19335 |          0 |             0 |          0 |                    1 |                0 |
|     19336 | t_263_r_4611686018427387904 | t_263_r_5764607523034234880 |     19337 |              15 | 19337, 19338, 19339, 19340, 19341 |          0 |             0 |          0 |                    1 |                0 |
|     19342 | t_263_r_5764607523034234880 | t_263_r_6917529027641081856 |     19343 |              15 | 19343, 19344, 19345, 19346, 19347 |          0 |             0 |          0 |                    1 |                0 |
|     19348 | t_263_r_6917529027641081856 | t_263_r_8070450532247928832 |     19349 |              15 | 19349, 19350, 19351, 19352, 19353 |          0 |             0 |          0 |                    1 |                0 |
|     19294 | t_263_r_8070450532247928832 | t_264_                      |     19295 |              15 | 19295, 19296, 19297, 19298, 19299 |          0 |            27 |          0 |                    1 |                0 |
|     19360 | t_264_                      | t_264_r_1152921504606846976 |     19361 |              15 | 19361, 19362, 19363, 19364, 19365 |          0 |             0 |          0 |                    1 |                0 |
|     19366 | t_264_r_1152921504606846976 | t_264_r_2305843009213693952 |     19367 |              15 | 19367, 19368, 19369, 19370, 19371 |          0 |             0 |          0 |                    1 |                0 |
|     19372 | t_264_r_2305843009213693952 | t_264_r_3458764513820540928 |     19373 |              15 | 19373, 19374, 19375, 19376, 19377 |          0 |             0 |          0 |                    1 |                0 |
|     19378 | t_264_r_3458764513820540928 | t_264_r_4611686018427387904 |     19379 |              15 | 19379, 19380, 19381, 19382, 19383 |          0 |             0 |          0 |                    1 |                0 |
|     19384 | t_264_r_4611686018427387904 | t_264_r_5764607523034234880 |     19385 |              15 | 19385, 19386, 19387, 19388, 19389 |          0 |             0 |          0 |                    1 |                0 |
|     19390 | t_264_r_5764607523034234880 | t_264_r_6917529027641081856 |     19391 |              15 | 19391, 19392, 19393, 19394, 19395 |          0 |             0 |          0 |                    1 |                0 |
|     19396 | t_264_r_6917529027641081856 | t_264_r_8070450532247928832 |     19397 |              15 | 19397, 19398, 19399, 19400, 19401 |          0 |             0 |          0 |                    1 |                0 |
|     19300 | t_264_r_8070450532247928832 | t_265_                      |     19301 |              15 | 19301, 19302, 19303, 19304, 19305 |          0 |            27 |          0 |                    1 |                0 |
|     19402 | t_265_                      | t_265_r_1152921504606846976 |     19403 |              15 | 19403, 19404, 19405, 19406, 19407 |          0 |             0 |          0 |                    1 |                0 |
|     19408 | t_265_r_1152921504606846976 | t_265_r_2305843009213693952 |     19409 |              15 | 19409, 19410, 19411, 19412, 19413 |          0 |             0 |          0 |                    1 |                0 |
|     19414 | t_265_r_2305843009213693952 | t_265_r_3458764513820540928 |     19415 |              15 | 19415, 19416, 19417, 19418, 19419 |          0 |             0 |          0 |                    1 |                0 |
|     19420 | t_265_r_3458764513820540928 | t_265_r_4611686018427387904 |     19421 |              15 | 19421, 19422, 19423, 19424, 19425 |          0 |             0 |          0 |                    1 |                0 |
|     19426 | t_265_r_4611686018427387904 | t_265_r_5764607523034234880 |     19427 |              15 | 19427, 19428, 19429, 19430, 19431 |          0 |             0 |          0 |                    1 |                0 |
|     19432 | t_265_r_5764607523034234880 | t_265_r_6917529027641081856 |     19433 |              15 | 19433, 19434, 19435, 19436, 19437 |          0 |             0 |          0 |                    1 |                0 |
|     19438 | t_265_r_6917529027641081856 | t_265_r_8070450532247928832 |     19439 |              15 | 19439, 19440, 19441, 19442, 19443 |          0 |             0 |          0 |                    1 |                0 |
|     19306 | t_265_r_8070450532247928832 | t_266_                      |     19307 |              15 | 19307, 19308, 19309, 19310, 19311 |          0 |            27 |          0 |                    1 |                0 |
+-----------+-----------------------------+-----------------------------+-----------+-----------------+-----------------------------------+------------+---------------+------------+----------------------+------------------+
24 rows in set (0.04 sec)

MySQL [test]> alter table tt truncate partition p3;

2. What did you expect to see? (Required)

show table tt regions command displays 24 regions

3. What did you see instead (Required)

MySQL [test]> show table tt regions;
+-----------+-----------------------------+-----------------------------+-----------+-----------------+-----------------------------------+------------+---------------+------------+----------------------+------------------+
| REGION_ID | START_KEY                   | END_KEY                     | LEADER_ID | LEADER_STORE_ID | PEERS                             | SCATTERING | WRITTEN_BYTES | READ_BYTES | APPROXIMATE_SIZE(MB) | APPROXIMATE_KEYS |
+-----------+-----------------------------+-----------------------------+-----------+-----------------+-----------------------------------+------------+---------------+------------+----------------------+------------------+
|     19312 | t_263_                      | t_263_r_1152921504606846976 |     19313 |              15 | 19313, 19314, 19315, 19316, 19317 |          0 |             0 |          0 |                    1 |                0 |
|     19318 | t_263_r_1152921504606846976 | t_263_r_2305843009213693952 |     19319 |              15 | 19319, 19320, 19321, 19322, 19323 |          0 |             0 |          0 |                    1 |                0 |
|     19324 | t_263_r_2305843009213693952 | t_263_r_3458764513820540928 |     19325 |              15 | 19325, 19326, 19327, 19328, 19329 |          0 |             0 |          0 |                    1 |                0 |
|     19330 | t_263_r_3458764513820540928 | t_263_r_4611686018427387904 |     19331 |              15 | 19331, 19332, 19333, 19334, 19335 |          0 |             0 |          0 |                    1 |                0 |
|     19336 | t_263_r_4611686018427387904 | t_263_r_5764607523034234880 |     19337 |              15 | 19337, 19338, 19339, 19340, 19341 |          0 |             0 |          0 |                    1 |                0 |
|     19342 | t_263_r_5764607523034234880 | t_263_r_6917529027641081856 |     19343 |              15 | 19343, 19344, 19345, 19346, 19347 |          0 |             0 |          0 |                    1 |                0 |
|     19348 | t_263_r_6917529027641081856 | t_263_r_8070450532247928832 |     19353 |              17 | 19349, 19350, 19351, 19352, 19353 |          0 |             0 |          0 |                    1 |                0 |
|     19294 | t_263_r_8070450532247928832 | t_264_                      |     19295 |              15 | 19295, 19296, 19297, 19298, 19299 |          0 |             0 |          0 |                    1 |                0 |
|     19360 | t_264_                      | t_264_r_1152921504606846976 |     19361 |              15 | 19361, 19362, 19363, 19364, 19365 |          0 |             0 |          0 |                    1 |                0 |
|     19366 | t_264_r_1152921504606846976 | t_264_r_2305843009213693952 |     19367 |              15 | 19367, 19368, 19369, 19370, 19371 |          0 |             0 |          0 |                    1 |                0 |
|     19372 | t_264_r_2305843009213693952 | t_264_r_3458764513820540928 |     19373 |              15 | 19373, 19374, 19375, 19376, 19377 |          0 |             0 |          0 |                    1 |                0 |
|     19378 | t_264_r_3458764513820540928 | t_264_r_4611686018427387904 |     19379 |              15 | 19379, 19380, 19381, 19382, 19383 |          0 |             0 |          0 |                    1 |                0 |
|     19384 | t_264_r_4611686018427387904 | t_264_r_5764607523034234880 |     19385 |              15 | 19385, 19386, 19387, 19388, 19389 |          0 |             0 |          0 |                    1 |                0 |
|     19390 | t_264_r_5764607523034234880 | t_264_r_6917529027641081856 |     19395 |              17 | 19391, 19392, 19393, 19394, 19395 |          0 |            39 |          0 |                    1 |                0 |
|     19396 | t_264_r_6917529027641081856 | t_264_r_8070450532247928832 |     19397 |              15 | 19397, 19398, 19399, 19400, 19401 |          0 |             0 |          0 |                    1 |                0 |
|     19300 | t_264_r_8070450532247928832 | t_265_                      |     19301 |              15 | 19301, 19302, 19303, 19304, 19305 |          0 |             0 |          0 |                    1 |                0 |
|     19450 | t_267_                      | t_268_                      |     19451 |              15 | 19451, 19452, 19453, 19454, 19455 |          0 |             0 |          0 |                    1 |                0 |
+-----------+-----------------------------+-----------------------------+-----------+-----------------+-----------------------------------+------------+---------------+------------+----------------------+------------------+
17 rows in set (0.04 sec)

4. What is your TiDB version? (Required)

MySQL [test]> SELECT tidb_version();
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tidb_version()                                                                                                                                                                                                                                                                                                                           |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Release Version: v6.1.2-20230301
Edition: Enterprise
Git Commit Hash: 38e7d898f2128dc3dd8324f44b6a8586f0e93106
Git Branch: heads/refs/tags/v6.1.2-20230301
UTC Build Time: 2023-03-01 08:51:06
GoVersion: go1.18.10
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)