Can I create a row sequence number in a derived column transform?

Hello John,

Why not use our transform?

http://www.sqlis.com/default.aspx?93


Allan

John Grant wrote:
No.

Row Number Transformation
(http://www.sqlis.com/default.aspx?93)

--
Darren
http://www.sqldts.com
http://www.sqlis.com

Nice transform, but if I am going to process through the data twice, once
with the derived column an once with your transform, then why not just save
the data from the derived tranform in a table and use execute SQL to create a
sequesnce column?

Also, can't I just add a function that the derived column transform can see
and use that . For example, derived column =
MySeqFunc([user::counter],increment)

thanks
-John

"Darren Green" wrote:

Hello John,

You cannot add a function to the derived column transform to derive an auto
incrementing number. You wouldn't be going through the data twice. It would
be one pipeline. Both of these components are Synchronous components and
as such are lightning quick. When you talk about using TSQL are you meaning
that you would stage the data to get the values before moving it on to your
real table? This would be expensive, almost certainly more so that the transforms.




Allan

I am not sure I understand. If I use 2 transforms is record 1 processed by
transform1 then transform2, then record 2, etc. Or is record 1-n processed
by transform1, then record 1-n processed by tranforms2? If the later is true
and my dataset exceeds memory will the results from tranform 1 not be written
to disk? If they are then is SQL Server that much more expensive.

Thanks for the help.

p.s. what a bummer you can't add functions to the derived column tranforms.


"Allan Mitchell" wrote:

Hello John,

These are sync components so what happens is the rows flow into T1. You
have what is know as a buffer. When T1's buffer overfills it passes them
downstream. T1's buffer is immediately filled by the next rows. They move
as memory. They are very very very fast. A Sync transform has next to no
effect on perf.

Comparing Overhead On The Execution Methods
(http://www.sqlis.com/default.aspx?84)


Allan