Tags for statement
Better approach for the given problem
Hi Masters, I am looking for a better approach for the below requirement with out using Union Input table:  (total volume will be 100 million records) Col1 Col2 Col3 1 1 1 1 2 2 1 2
sql statement problem approach better
Conditional (case statement) Join Criteria
I'm relatively new to database development in general and I've got a question related to the use of CASE statements when joining tables. Here's the situation I'm faced with. I have a table (T1) that looks like this: key1 key2 key3 key4 aaa zz 1 2 aaa zz 2 3 bbb yy 2 3 ccc xx 3 4 And another table (T2) that looks like this: key1 key2 key3 key4 aaa zz 1 2 bbb yy ^ ^ ccc xx 3 ^ As you can see the keys in T2 are not always the same as T1 (don't ask why). But I need to use as many of the keys as I can in the join. What I coded is this: ON T1.key1 = T2.key1
join case statement