Difference between ETL developer and Datawarehouse developer

Peace · Post by **Peace** » Thu Sep 21, 2006 6:55 pm

Dear all,

I am so sorry for asking non-technical question.I don't know where can I ask this question and so I have to post here.
I just want to curious.
Do u know what is the difference between ETL developer and Data warehouse developer?

I am very confusing about these 2 position here.
If u know,could you pls share me?

Cheers!!!

vmcburney · Post by **vmcburney** » Thu Sep 21, 2006 7:12 pm

ETL is used for a lot more projects than DW. It is also used for data migrations, data conversions, data quality, CDI, DSS, Master data management etc. DW is just a subset of the work ETL can do.

On a DW project you can get away with ETL coders who do not know DW as long as you have data modelling experts on hand to explain things like surrogate keys and slowly changing dimensions so the ETL developer can design the jobs correctly.

Organisations doing large scale DWs tend to ask for ETL developers who have worked on DWs before to ensure they get people with the right skills to do the job.

Peace · Post by **Peace** » Thu Sep 21, 2006 7:49 pm

Do you mean DW developer should have to know not only ETL but also data modelling?

vmcburney wrote:ETL is used for a lot more projects than DW. It is also used for data migrations, data conversions, data quality, CDI, DSS, Master data management etc. DW is just a subset of the work ETL can do.

On a DW project you can get away with ETL coders who do not know DW as long as you have data modelling experts on hand to explain things like surrogate keys and slowly changing dimensions so the ETL developer can design the jobs correctly.

Organisations doing large scale DWs tend to ask for ETL developers who have worked on DWs before to ensure they get people with the right skills to do the job.

vmcburney · Post by **vmcburney** » Thu Sep 21, 2006 7:51 pm

An ETL developer on a DW project should know both ETL and DW concepts. On the modelling side they should know about things like surrogate keys, dimensional modelling and slowly changing dimensions. At least one ETL developer on the project should have both skillsets.

Peace · Post by **Peace** » Thu Sep 21, 2006 8:47 pm

I see.Thank you so much for your response and time

vmcburney wrote:An ETL developer on a DW project should know both ETL and DW concepts. On the modelling side they should know about things like surrogate keys, dimensional modelling and slowly changing dimensions. At least one ETL developer on the project should have both skillsets.

kumar_s · Post by **kumar_s** » Thu Sep 21, 2006 9:50 pm

The same time, in DW Project, ETL will play considerable role, but ETL alone doesnt make DW.

koolnitz · Post by **koolnitz** » Fri Sep 22, 2006 12:04 am

As said by Kumar, ETL ends at loading the data into a database called as data warehouse. But what's the use of data when it cannot be converted as information! DW includes ETL plus reporting for analysis (in most cases). People usually go for OLAP tools like Cognos, Business Objects for reporting purpose.

In other words, ETL is a subset of data warehousing.

ray.wurlod · Post by **ray.wurlod** » Fri Sep 22, 2006 4:15 am

I disagree. An ETL developer need have no interaction with a data warehouse at all. It is also possible to create and populate a data warehouse without using any ETL (for example by using an ELT approach).

gateleys · Post by **gateleys** » Fri Sep 22, 2006 7:56 am

Try this one:
ETL developer - One who develops ETL tools like DataStage, Informatica, etc.

How about that?

9kim · Post by **9kim** » Sun Jan 28, 2007 2:18 pm

koolnitz wrote:... ETL ends at loading the data into a database called as data
warehouse. But what's the use of data when it cannot be converted as information!
DW includes ETL plus reporting for analysis (in most cases).
People usually go for OLAP tools like Cognos, Business Objects for reporting purpose.
In other words, ETL is a subset of data warehousing.

I am agree with you. A DW-developer must live with the staging-layer
(modell) the ETL-developer lefts behind. Oft a DW-developer has to build his own output-layer to satisfate his reporting-goal (frontend like Cognos, BO ...).

ray.wurlod wrote:I disagree.
An ETL developer need have no interaction with a data warehouse at all.
It is also possible to create and populate a data warehouse without using any ETL
(for example by using an ELT approach).

You can use SAS or somes PL/SQL to populate a data warehouse without Datastage, but it still be an ETL-process (and behind this an ETL-developer).
But you can use DS for the datamigration, so you don't have any interaction with a DW.