def METHOD_NAME(self, schema):
    query = "SELECT database, table, name FROM system.columns WHERE database NOT IN ('system')"
    results, error = self.run_query(query, None)
    if error is not None:
        self._handle_run_query_error(error)
    results = json_loads(results)
    for row in results["rows"]:
        table_name = "{}.{}".format(row["database"], row["table"])
        if table_name not in schema:
            schema[table_name] = {"name": table_name, "columns": []}
        schema[table_name]["columns"].append(row["name"])
    return list(schema.values())