Exclude some files when requesting directory

Currently Drill ignores files starting with dot ('.') or underscore ('_').

When requesting directory with file of different types or different schema and present at multiple levels of the tree file, it will be useful/more flexible, to have also option(s) to exclude some files by extension or maybe with a regexp.

For Example:

myTable
|--D1
   |--file1.csv
   |-file2.csv
|--D2
   | SubD2
      |--file1.csv
   |--file1.csv
   |--file1.xml 
   |--file1.json

without enter in a debate of what is a good the organisation/disposition for the data, currently to request all the csv files of this example, the way is:

SELECT * FROM ....`myTable/*/*.csv`
UNION
SELECT * FROM ....`myTable/*/*/*.csv`

It will be useful to have the capacity to request directly myTable like:

/* ALTER SESSION SET exclude_files='xml,json' */
/* or */
/* ALTER SESSION SET only_files='csv' */
SELECT * FROM myTable