While running query below against voter_hive (drill table), where contributions field is defined as "float" (4 byte floating point number in drill) I get a value of SUM that is different from result generated by postgres.
1. Query + result generated by Postgres (queries.tar)
2. voter_hive parquet file
3. create_table.tar - contains CTAS statement + csv file (if you want to create table yourself)