there's mysql database generated automatically while using config -f "*.*"

[minipeanut]

Bug Report

1. What did you do? If possible, provide a recipe for reproducing the error.

./dumpling -u root -h xx -P 4000 -o /data0/dumpling/test0001/ -f "."

2. What did you expect to see?

3. What did you see instead?
   

4. Versions of the cluster

   • Dumpling version (run dumpling -V):

     Release version: v5.0.0-nightly
     Git commit hash: a0bbe7c67b41dfcfa2cedfd97ddde956863b35ef
     Git branch:      heads/refs/tags/v5.0.0-nightly
     Build timestamp: 2021-03-29 02:46:06Z
     Go version:      go version go1.13 linux/amd64
     

   • Source database version (execute SELECT version(); in a MySQL client):

     5.7.25-TiDB-v5.0.0-nightly
     

[lichunzhu]

This is an expected behavior to support dumping system tables. The default --filter configuration will exclude all these system tables.
default --filter:
-f *.* -f !/^(mysql|sys|INFORMATION_SCHEMA|PERFORMANCE_SCHEMA|METRICS_SCHEMA|INSPECTION_SCHEMA)$/.*

[cyliu0]

@lichunzhu Should we change the document mentioned in this issue?

[lichunzhu]

@lichunzhu Should we change the document mentioned in this issue?

Yes. We need to update this document.