I am getting duplicates sometimes in table. Let me tell you my scenario with example so that it would be helpful for me to get answers.
I have three tables Stage1, Stage2 and Final_Stage. I have simple procedure which loads into these three tables.
Final_Stage table is a union of Stage1 and Stage2 ( select * from Stage1 union Select * from Stage2)
example records in staging tables:
Stage1
1
2
3
4
5
Stage2
3
4
5
6
7
After doing the Union the desired output in Final_Stage is 1
2
3
4
5
6
7
but sometimes i am getting duplicates in Final_Stage tables.
my question is if CPU utilization of DB machine is 100 % or DB load is high does "Union" don't work at all(will it give duplicates instead of distinct records) What would be the scenario and how to handle . Please help me ..
Thanks,
Sandeep C