Explain analyze delete executation is slow

[Connor1996]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

• sysbench prepare with 10000000 rows
• run

for i in 1..1000 {
     mysql -uroot -D sbtest -e "explain analyze delete from sbtest where id < i * 10000;"
}

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

The total process key is 10000

3. What did you see instead (Required)

The total process key is far beyond 10000, and the coprocess cache hit is 0. And if I sleep 1s between rounds, the total process key is 10000 and executes fast.

4. What is your TiDB version? (Required)

Release Version: v6.3.0-alpha
Edition: Community
Git Commit Hash: 8b5b724d8a932239303a1d0ba547323eb0e5161b
Git Branch: heads/refs/tags/v6.3.0-alpha
UTC Build Time: 2022-08-19 14:31:05
GoVersion: go1.18.5
Race Enabled: false
TiKV Min Version: 6.2.0-alpha
Check Table Before Drop: false