Unrelated DDL change cause cache miss and reload in infoschema v2

[tiancaiamao]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

As the title says, that kind of behavior is not expected.

For example, if I have a table t1
I do some unrelated DDL operations
Visiting t1 should still always hit cache

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

create table t1 (id int);
select * from t1; // hit infoschema cache
// evit the schema cache of t1
create table t2 (id int);
select * from t1;
select * from t1; // hit infoschema cache because DDL is on t2, unrelated to t1
create table t3 (id int);
select * from t1; // hit infoschema cache because DDL is on t3, unrelated to t1
create table t4 (id int);
select * from t1;; // hit infoschema cache because DDL is on t4, unrelated to t1

3. What did you see instead (Required)

After the original t1 cache been evicted, the following DDL operation would cause schema cache miss everytime.

4. What is your TiDB version? (Required)

master