ALTER DATABASE ... SET TIFLASH REPLICA will add tiflash replica to SEQUENCE table unexpectly

[JaySon-Huang]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

test> create database testdb;
test> use testdb;
testdb> CREATE SEQUENCE seq;

-- adding tiflash replica to sequence table is blocked
testdb> alter table seq set tiflash replica 1;
(1347, "'testdb.seq' is not BASE TABLE")
testdb> select * from information_schema.tiflash_replica;
+--------------+--------------------------+----------+---------------+-----------------+-----------+----------+
| TABLE_SCHEMA | TABLE_NAME               | TABLE_ID | REPLICA_COUNT | LOCATION_LABELS | AVAILABLE | PROGRESS |
+--------------+--------------------------+----------+---------------+-----------------+-----------+----------+
+--------------+--------------------------+----------+---------------+-----------------+-----------+----------+

-- adding tiflash replica to sequence table is added unexpectedly
testdb> alter database testdb set tiflash replica 1;
testdb> select * from information_schema.tiflash_replica;
+--------------+--------------------------+----------+---------------+-----------------+-----------+----------+
| TABLE_SCHEMA | TABLE_NAME               | TABLE_ID | REPLICA_COUNT | LOCATION_LABELS | AVAILABLE | PROGRESS |
+--------------+--------------------------+----------+---------------+-----------------+-----------+----------+
| testdb       | seq                      | 644      | 1             |                 | 1         | 1.0      |
+--------------+--------------------------+----------+---------------+-----------------+-----------+----------+

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

executing ALTER DATABASE ... SET TIFLASH REPLICA will not add tiflash replica for SEQUENCE table in the database.
And warnings show that the SEQUENCE table is ignored.

3. What did you see instead (Required)

-- adding tiflash replica to sequence table is added unexpectedly
testdb> alter database testdb set tiflash replica 1;
testdb> select * from information_schema.tiflash_replica;
+--------------+--------------------------+----------+---------------+-----------------+-----------+----------+
| TABLE_SCHEMA | TABLE_NAME               | TABLE_ID | REPLICA_COUNT | LOCATION_LABELS | AVAILABLE | PROGRESS |
+--------------+--------------------------+----------+---------------+-----------------+-----------+----------+
| testdb       | seq                      | 644      | 1             |                 | 1         | 1.0      |
+--------------+--------------------------+----------+---------------+-----------------+-----------+----------+

4. What is your TiDB version? (Required)

affects v6.1 ~ current master

testdb> select tidb_version() \G
***************************[ 1. row ]***************************
tidb_version() | Release Version: v8.0.0-alpha-561-gf4e366e
Edition: Community
Git Commit Hash: f4e366ea0c38d0bea20da9d8bc1f55252c991324
Git Branch: HEAD
UTC Build Time: 2024-03-19 13:40:56
GoVersion: go1.21.4
Race Enabled: false
Check Table Before Drop: false
Store: tikv

[CalvinNeo]

Add check for sequence in ModifySchemaSetTiFlashReplica

[windtalker]

Change to sig/sql-infra since it should be a ddl related bug