In our SSIS package we have a lot of stored procedures which get called via a SQL task. These SP's sometimes have a union all or joins between lots of tables before inserting into a final table.
If I change the entire flow into merge,merge join and other tasks, will it improve my performance in any way? Or would SQL tasks be better and faster?
SQL Server is better at set-based operations like JOIN, ORDER BY and any form of aggregation 99% of the time - it's what it was designed to do. The final INSERT, however, may be faster in SSIS, which is optimised for large, fast inserts.
Help us to help you. For better, quicker and more-focused answers to your questions, consider following the advice in this
If the answer to your question can be found with a brief Google search, please perform the search yourself, rather than expecting one of the SSC members to do it for you.
Please surround any code or links you post with the appropriate IFCode formatting tags. It helps readability a lot.