Tidb: update auto_random_base in 'show create table' after insertion

Created on 27 May 2020 · 3Comments · Source: pingcap/tidb

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

drop table if exists t;
create table t (a bigint primary key auto_random(5), b int unique key auto_increment) auto_random_base = 100, auto_increment = 100;
insert into t values (1000);
show create table t;

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

The AUTO_RANDOM_BASE part should be updated to a larger value:

+-------+--------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table                                                                                                                         |
+-------+--------------------------------------------------------------------------------------------------------------------------------------+
| t     | CREATE TABLE `t` (                                                                                                                   |
|       |   `a` bigint(20) NOT NULL /*T![auto_rand] AUTO_RANDOM(5) */,                                                                         |
|       |   `b` int(11) NOT NULL AUTO_INCREMENT,                                                                                               |
|       |   PRIMARY KEY (`a`),                                                                                                                 |
|       |   UNIQUE KEY `b` (`b`)                                                                                                               |
|       | ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin  AUTO_INCREMENT=2000100 /*T![auto_rand_base] AUTO_RANDOM_BASE=2000100 */ |
+-------+--------------------------------------------------------------------------------------------------------------------------------------+

3. What did you see instead (Required)

AUTO_RANDOM_BASE is still 100.

+-------+---------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table                                                                                                                    |
+-------+---------------------------------------------------------------------------------------------------------------------------------+
| t     | CREATE TABLE `t` (                                                                                                              |
|       |   `a` bigint(20) NOT NULL /*T![auto_rand] AUTO_RANDOM(5) */,                                                                    |
|       |   `b` int(11) NOT NULL AUTO_INCREMENT,                                                                                          |
|       |   PRIMARY KEY (`a`),                                                                                                            |
|       |   UNIQUE KEY `b` (`b`)                                                                                                          |
|       | ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin AUTO_INCREMENT=2000100 /*T![auto_rand_base] AUTO_RANDOM_BASE=100 */ |
+-------+---------------------------------------------------------------------------------------------------------------------------------+