Hi,
Can anyone please tell which one will improve session performance if we have 'Union' and 'Union All' in the same mapping.
For example, if we have two tables A and B then
(1) 'A UNION B' gives all DISTINCT recs from both the tables. Here to get the disticnt recs also will take time.
(2) 'A UNION ALL B' gives ALL(not distinct) recs from both tables and again it would take time to load into target table which has key constraints.Here also it wil time to do this operation.
This leads to a confusion which technique will improve session performace?
Thanks,
Ravinuthala