topic Re: Slow Changing dimension in Talend Studio

Slow Changing dimension

Anonymous — Thu, 03 Jan 2013 14:47:18 GMT

Can someone please help me? I am rather new to Talend, and I am trying to take a set of positional files and create a historical view of them. I am trying to utilize the slow changing dimension function but can not get it to function properly. I keep getting an Invalid column name error, even if i change to a valid column. Please look at the pictures below. any help is much appreciated. Thanks.

Re: Slow Changing dimension

Anonymous — Thu, 03 Jan 2013 17:06:06 GMT

I have gotten past the unknown column name. now i am stuck with an error that reads;
SCDSK_tMSSQLSCD_8 cannot be resolved to a type.
Row1 cannot be resolved to a type.
Syntax error on toke ".", class expected after this token.

Does anyone have any ideas on how to resolve any of these errors?

Re: Slow Changing dimension

Anonymous — Thu, 03 Jan 2013 17:06:08 GMT

The SCD feature needs to know what is the source key to detect if an data set has been changed or not.
You have to declare which columns contains a key for the sources.
You can only find changes if you have something what keeps unchanged!

Re: Slow Changing dimension

Anonymous — Thu, 03 Jan 2013 17:10:29 GMT

jlolling
I have set a source key, for a column that is constant.
and now i am getting the errors that are in the picture attached.

Re: Slow Changing dimension

Anonymous — Thu, 03 Jan 2013 17:31:25 GMT

Yes, because you don't have changed the default settings from the SCD component.
SCD need two additional columns to store the timestamps when the dataset starts and when the dataset ends.
Add to your output table these both timestamp columns (best way call them like the component suggest).

Re: Slow Changing dimension

Anonymous — Thu, 03 Jan 2013 18:14:54 GMT

So if i rename them to EFF_DT and TERM_DT in my output and on the SCD it should work?

Re: Slow Changing dimension

Anonymous — Thu, 03 Jan 2013 19:11:22 GMT

of i think i have it almost there but i can not get rid of this last error. it says errorMessage cannot be resolved or is not a field.
I have taken the error message portion off my mapping on input and outputs and i still recieve the error.

Re: Slow Changing dimension

Anonymous — Tue, 15 Jan 2013 20:01:28 GMT

Ok i am still strugling with this i am almost there though. I now just can not get my surrogate key to populate or the dates for my scd_start and scd_end. below are some screen shots please let me know if you can help out in any way.

Re: Slow Changing dimension

Anonymous — Wed, 20 Mar 2013 10:20:02 GMT

You have to provide the name of the surrogate key column defined in the Dimension table to SCD editor of tMySQLSCD component.
For more details on Implementing SCD using Talend visit following links:
SCD (Slowly Changing Dimensions) Type 1
http://vikramtakkar.blogspot.com/2013/03/implementing-scd-type-1-slowly-changing.html
SCD (Slowly Changing Dimensions) Type 2
http://vikramtakkar.blogspot.com/2013/03/implementing-scd-slowly-changing.html
SCD (Slowly Changing Dimensions) Type 3
http://vikramtakkar.blogspot.com/2013/03/implementing-slowly-changing-dimensions.html
Regards
Vikram Takkar
http://vikramtakkar.blogspot.com
skype: vikram.takkar