hawkingrei
commented
2 months ago Open hawkingrei opened 2 months ago
hawkingrei
commented
2 months ago 
cfzjywxk
commented
2 months ago @you06 Is this introduced by the recent refactor?
you06
commented
1 month ago @you06 Is this introduced by the recent refactor?
This is not introduced by the refactor, I made a reproduce test and found that this race also happens in TiDB 8.1
func TestMemDBRaceInUnionExec(t *testing.T) {
store := testkit.CreateMockStore(t)
tk := testkit.NewTestKit(t, store)
tk.MustExec("use test")
tables := 5
for i := 0; i < tables; i++ {
tk.MustExec(fmt.Sprintf("create table t%d(id int primary key, v int)", i))
}
tk.MustExec("insert into t0 values(1, 1), (2, 2), (3, 3), (4, 4)")
for i := 1; i < tables; i++ {
tk.MustExec(fmt.Sprintf("insert into t%d select * from t0", i))
}
tk.MustExec("set tidb_pessimistic_txn_fair_locking=0")
for i := 0; i < 1001; i++ {
tk.MustExec("begin pessimistic")
tk.MustQuery(`select * from t0 where id = 1 for update union
select * from t1 where id = 1 for update union
select * from t2 where id = 1 for update union
select * from t3 where id = 1 for update union
select * from t4 where id = 1 for update`)
tk.MustExec("rollback")
}
}
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