Close -

I think the problem is backup_MB is integer.
So the result of backup_MB/1024 is defined to be integer.
I think you need to cast backup_MB to decimal BEFORE you divide it:

select SUM(cast(A2.backup_mb) as decimal(8,2))) /1024 as "MB_Backup_WinNT"
from
nodes A1, auditocc A2 where A1.node_name=A2.node_name AND
A1.platform_name='WinNT'