Server Lookup

tunde · Post by **tunde** » Mon Jun 23, 2003 8:25 am

Hi all,
Can someone explain to me how lookups are performed thru server jobs?
I dont see any stage that does it.
An example would also be appreciated.

Thanks /

Tunde.

Tunde

chulett · Post by **chulett** » Mon Jun 23, 2003 10:35 am

Tunde,

No offense, but your questions are *so* basic you really should look into taking a class. Either that or at least work thru the tutorial, it would certainly help.

-craig

ray.wurlod · Post by **ray.wurlod** » Mon Jun 23, 2003 4:38 pm

Lookups are performed by a Transformer stage that has more than one input.
One input is the stream of data being processed, the other inputs are reference input links. On these you generate a value for the lookup key, using an expression. Or more than one, if there is more than one key.
For lookups based on primary key, a local hashed file (on the other end of the reference input link) delivers the fastest lookup capability.
For lookups based on secondary key, where multiple rows may be returned, only the ODBC or UV stage types support the required functionality.

(Do I guess South African origin from your name?)

Ray Wurlod
Education and Consulting Services
ABN 57 092 448 518

chulett · Post by **chulett** » Mon Jun 23, 2003 4:51 pm

Sorry, I should have put some kind of *helpful* reply in there as well. [:I] Today was not... pleasant.

Thanks to Ray for providing a coherent reply, as always.

-craig

vmcburney · Post by **vmcburney** » Mon Jun 23, 2003 6:30 pm

Next time Craig try and put in a couple of these [:(!][:(!] and maybe one of these [V], it will have more impact. He'll be reading that manual so fast his eyes will spin.

Vincent McBurney
Data Integration Services
www.intramatix.com

tunde · Post by **tunde** » Tue Jun 24, 2003 8:21 am

Ray, I just want to thank you for answering my question.

Chulett and Vmcburney -
I dont know who you guys think you are but you are not being ethical about your replies. if you think my questions are too basic, you do not have to answer it neither do you need to be rude about it.
Yes, im new to datastage but i would like to let you know that i have more than 5years of experience in ETL, implementing other tools like Informatica and Albinitio.
And for the record. i did go to class but the only training i got from the class was i think an overview of the tool. its not detail enough to let me know some of this things. Right now im learning and i believe im doing pretty well. i do not need you people's advice. im sure people like RAY who really want to help would help inexperienced people like us and we definitely appreciate them.

Thanks again Ray.

Tunde

chulett · Post by **chulett** » Tue Jun 24, 2003 1:22 pm

Err... ok. Not sure what exactly was so "unethical" about my reply. [:0] Heck, I even apologized for not providing an example in my second post.

Just trying to point out that this forum (and the Oliver list) are not really meant to be a substitute for training. And a class that was only an "overview of the tool" is not much different from no class at all - so even more so a run thru the tutorial would do you a world of good. All In My Humble Opinion, of course.

That wasn't meant to be disparaging or any slur on your abilities, so please don't take it that way. It was just an honest opinion of how best to get up to speed on the tool.

-craig

vmcburney · Post by **vmcburney** » Tue Jun 24, 2003 7:05 pm

I'm sorry you took offence, I was joking about Craig's brisk reply, not about your question. I've got to remember that humour can be misunderstood on a forum as people can read it in a different tone. I have happily answered this same question on this forum before and I've never criticized a question.

Vincent McBurney
Data Integration Services
www.intramatix.com

Nat · Post by **Nat** » Sat Jul 12, 2003 2:44 am

Hi,
the turorial I have, does not contain excercises about look up. There are explanations in the pdf (but they are not sufficient to work with look up).
If any of you has documentation or exercise about it, please send me it. Similarly, I haven't found any kind of information about surrogate key.
I worked with others ETL tools before, and documentation was very rich.
Thank you very much for your attention, bye.

kcbland · Post by **kcbland** » Sat Jul 12, 2003 8:30 am

There is an electronic course offered by Ascential that takes you through building a framework for your ETL application. The course DS306 was designed to give at least a starting point to using the tool in such a way as to design your ETL application to handle surrogate keys, slowly changing dimensions, instantiate-able jobs, restart capability, etc. Anyone struggling through these issues would benefit from having their company purchase an E-copy of the course.

I know the course well because I was part of the four man team who created the framework, supporting jobs and libraries, and coursework. The course is based on DataStage Server Edition, while Tunde is using PX, he and Nat are absolute examples of why we developed this course. A tool is analagous to a programming language. You have to develop common/shared libraries, standards and best practices, etc, before starting any large development effort. Not having a background on the tool from which to draw can be challenging for anyone when starting any development effort.

I would also suggest that Tunde has had the hardest effort of everyone out there. He's learning both DataStage Server and PX. These are completely different paradigms, and he basically has to learn 2 new ETL tools. He also has no PX resources out here to draw from, because DS PX is so new most people are still working on their first large scale project using it. By next year there will be more seasoned and blooded PX warriors who will have discovered the best practices, standards, tricks, etc. In addition, Ascential will have improved their course work and should be able to offer better guidance.

Hang in their Tunde.

Kenneth Bland

Nat · Post by **Nat** » Sun Jul 13, 2003 6:25 am

Hi Kenneth,
I'm interested in the electronic course you talked about. I have to compare two ETL tools (for a degree), analyzing how it is possible to implement, with them, some theoretical aspect of data warehousing.
But the first one (Informatica) has a rich documentation, but the second one (DS) hasn't it.
I'm also interested in buying the DS tool, so I want to evaluate it.
In this I'm self-educating, and time to do this is not much so here I am in this forum.
I have not the tool for the moment, I see it as guest in two firms that host me.

If you know, please give me information on buying the course.

Thank you very much for your attention. Bye.

kcbland · Post by **kcbland** » Sun Jul 13, 2003 7:38 am

Start here: http://www.ascential.com/services/education.html and go further.

Kenneth Bland

ray.wurlod · Post by **ray.wurlod** » Sun Jul 13, 2003 6:24 pm

When you buy the tool, you will discover that DataStage, too, has a rich set of documentation. Some manuals install with the client software. Manuals for the optional ("plug-in") components come with those components; you can install these with the regular set if you wish. In addition, DataStage has one of the best on-line help systems I have ever used, with not only reference topics but also "how to" topics.
As far as I know the documentation is not available separately but, if you make your situation known the Ascential Software, they may be able to assist.
Just out of curiosity, what degree are you pursuing that includes comparison of ETL tools? (You can reply off line to that if you prefer.)

Ray Wurlod
Education and Consulting Services
ABN 57 092 448 518