Now saffron.propertries file will be added into Drill conf directory which will define default encoding used to parse query string.
Another option to override saffron properties is to set them as system options. This will take higher priority then saffron.properties file.
Add to drill-env.sh:
NB!: the symbols $en_US must be preceded by \ character if one inserts the properties' row to drill-env.sh file, otherwise drill will stuck -> -Dsaffron.default.collation.name=ISO-8859-1\$en_US
This information should be also documented, probably in https://drill.apache.org/docs/data-type-conversion/.