Hi guys, even if I googled some article I did not yet understand how Merge Join works. See below:

I have got a table in financial with 10000 rows, I copied and pasted the table in the developing db and I removed just one customer (2728 rows). So we have table Financial 10000 rows, table developing 7272 rows. I sorted the rows (I tried with only one order, two orders..now I got six orders). I merged the table (only one link, two links, three links...etc) but the result is always the same 14828...which is the criteria? I do not understand...Thanks

Hi Diegoctn,

It depends on the type of join you use

• Left outer join: Includes all rows from the left table, but only matching rows from the right table. You can use the Swap Inputs option to switch data source, effectively creating a right outer join.
• Full outer join: Includes all rows from both tables.
• Inner join: Includes rows only when the data matches between the two tables.

Thanks Arthur. And that's why I am wondering why I move 14828 rows. It doesn't make any sense by the waay that the value in the tables are the same..

If you want one-to-one, you need to ensure the columns you join on make the row unique. Try doing a similar join in SQL and you should end up with the same number of rows as what the merge join is doing

Thanks, RyanAB. I know how the join works, that's why I am asking how the merge join works.

Thanks Arthur. And that's why I am wondering why I move 14828 rows. It doesn't make any sense by the waay that the value in the tables are the same..

If the values are the same by PK it is doing a UNION (not UNION ALL), add a surrogate key to include in the MERGE JOIN e.g. NEWID(), or add it in the package to the flow http://microsoft-ssis.blogspot.ca/2011/02/create-guid-column-in-ssis.html and then you will able to process all the rows.

If you are using Full Outer Join and you remove a record that is in both data flows, you will get this result.  Also if you use Left Outer Join and remove a record that is in the "Right" data flow you will get this result.

Thus the importance of Authur's question to solving this.

Thanks, RyanAB. I know how the join works, that's why I am asking how the merge join works.

?? It works like a join, you should be able to exactly replicate the functionality with a join