fail to notify DDL event and stats_meta is not created for the table

[aytrack]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

1. deploy a cluster
2. create a lot of table

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

1. create table success and no warn log

3. What did you see instead (Required)

get the warn log because the notify channel is full.

 [2022/05/25 23:12:18.813 +00:00] [WARN] [ddl.go:255] ["[ddl] fail to notify DDL event"] [event="(Event Type: create table, Table ID: 863784, Table Name archive_blob_2019_07"] 

4. What is your TiDB version? (Required)

ySQL [email protected]:(none)> select tidb_version()\G
***************************[ 1. row ]***************************
tidb_version() | Release Version: v6.1.0-alpha-282-g0c17a9acd
Edition: Community
Git Commit Hash: 0c17a9acdad0b0d6556f37048e9dafb281f58fab
Git Branch: HEAD
UTC Build Time: 2022-07-04 07:32:26
GoVersion: go1.18
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false

[winoros]

This would influence the accuracy of the statistics. But it's not very critical.