error_handler manage error messages for package
Arguments
- err
character, error message
- fun
character, function name where error happened
- step
integer, code identifying the step in the function where error happened. For dbTableFrom... functions steps are:
101,121: read file schema (DSV, Xlsx)
102: handle col_names and col_types
103: create empty table
104: read data
105: write data
106: indexing