12-27-2015 03:01 PM
How to join the 2 very large datasets with duplicate id keys in both the datasets
For example, I have the following datasets
acct_no a b c d
a1 4 7 2 8
a3 5 32 8 12
a5 42 12 54 65
a1 5 2 17 23
acct_no is the key with duplicates because it is a transaction dataset.
acct_no in table 2 also has duplicates because the logic is that a single customer can have more than one card, one a primary card and the other being secondary card
Can anybody help me with the logic for the join?
The datasets contain 400 million records and are pretty wide and long, however i need to fetch only the card_no from table2, so table 1 would be my left table. Sorting will not help either
12-27-2015 05:08 PM
Contents of this post seem like a duplicate.
But the title is totally different from the question?