3586794, create HashMap with correct initial size
3586794, create HashMap with correct initial size

All HashMaps returned from getEnvironment() are held in memory
so they can be sorted when "ORDER BY" is used.

Creating each HashMap with correct inital size avoids wasting memory.

Also create only one list of column names with the table alias included,
instead of creating "T.ID" for each row.

kwaxi/csvjdbc,kwaxi/csvjdbc