With the OLEDB source, is it wrong to use a table / view as a source and only check the columns required or is it beneficial to write a select col1, col2 etc etc as a SQL command?
I cannot see any difference in performance between the two.
Thanks.
Always always always use a SQL command so as to avoid the situation documented here: http://blogs.conchango.com/jamiethomson/archive/2006/02/21/2930.aspx I can't stress this enough.
Also check #4 here: http://blogs.conchango.com/jamiethomson/archive/2006/01/05/2554.aspx Basically, only pull in the data that you need otherwise performance will suffer.
-Jamie
|||Thanks Jamie but...I would still like to know the underlying reason it is bad :)
Accepted that Select * is bad due to many reasons but:
My "tables" are views which themselves only select columns required for the data flow and nothing more.
Basically I am being lazy - I write the columns out in the view and don't _really_ want to write them again in SSIS :)
From a performance point of view, the above method is exactly the same either way. I cannot and have not seen what you described.
Will play around some more and try find a reason (unless someone wants to save us the trouble....)|||
Well if nothing else I would do it in the interests of best practice. And also cos I'm picky - I hate seeing a selected table rather than a SQL statement :)
-Jamie
|||Jamie Thomson wrote:
Well if nothing else I would do it in the interests of best practice. And also cos I'm picky - I hate seeing a selected table rather than a SQL statement :)
-Jamie
A counter to that is I hate seeing any form of SQL in SSIS. Rather have the logic in a view / proc or just pull from the table. Make life easier when looking for bugs.
(yes, you could make a rule such as "do not use anything more that Select *" :)|||
Let's agree to disagree! :)
-J
