fix wrong regular expression

tidb-lightning/tidb-lightning-data-source.md

@@ -345,7 +345,7 @@ TiDB Lightning currently only supports Parquet files generated by Amazon Aurora
 ```
 [[mydumper.files]]
 # The expression needed for parsing Amazon Aurora parquet files
-pattern = '(?i)^(?:[^/]*/)*([a-z0-9_]+)\.([a-z0-9_]+)/(?:[^/]*/)*(?:[a-z0-9\-_.]+\.(parquet))$'
+pattern = '(?i)^(?:[^/]/)([a-z0-9\-_]+).([a-z0-9\-_]+)/(?:[^/]/)(?:[a-z0-9\-_.]+.(parquet))$'
 schema = '$1'
 table = '$2'
 type = '$3'
@@ -377,14 +377,14 @@ Take the Aurora snapshot exported to S3 as an example. The complete path of the
 
 Usually, `data-source-dir` is set to `S3://some-bucket/some-subdir/some-database/` to import the `some-database` database.
 
-Based on the preceding Parquet file path, you can write a regular expression like `(?i)^(?:[^/]*/)*([a-z0-9_]+)\.([a-z0-9_]+)/(?:[^/]*/)*(?:[a-z0-9\-_.]+\.(parquet))$` to match the files. In the match group, `index=1` is `some-database`, `index=2` is `some-table`, and `index=3` is `parquet`.
+Based on the preceding Parquet file path, you can write a regular expression like `(?i)^(?:[^/]/)([a-z0-9\-_]+).([a-z0-9\-_]+)/(?:[^/]/)(?:[a-z0-9\-_.]+.(parquet))$` to match the files. In the match group, `index=1` is `some-database`, `index=2` is `some-table`, and `index=3` is `parquet`.
 
 You can write the configuration file according to the regular expression and the corresponding index so that TiDB Lightning can recognize the data files that do not follow the default naming convention. For example:
 
 ```toml
 [[mydumper.files]]
 # The expression needed for parsing the Amazon Aurora parquet file
-pattern = '(?i)^(?:[^/]*/)*([a-z0-9_]+)\.([a-z0-9_]+)/(?:[^/]*/)*(?:[a-z0-9\-_.]+\.(parquet))$'
+pattern = '(?i)^(?:[^/]/)([a-z0-9\-_]+).([a-z0-9\-_]+)/(?:[^/]/)(?:[a-z0-9\-_.]+.(parquet))$'
 schema = '$1'
 table = '$2'
 type = '$3'