ETL Language Vs SQL

[connolly]

Hi

can any one be able to assist me in providing some basic info about the ETL language.

does the ETL tools use the standard SQL commands to extract , transform and load the data into the warehouse or does this ETL language differ from vendor to vendor ?

as all the RDBMS r SQL compatible, i guess atleast the extract part can be done using the SQL. what about the transforming and loading ?

I heard recently that SQL will be the industry standard for all the ETL tools. is it so?

I would greatly appreciate anybody who can provide me with this info as i had been BURNING my head with this Q .

thanks
Pat

 

[johnherman]

ETL is not a language. It stands for Extract Transform and Load.

ETL tools and their languages are proprietary, although each has an interface to call SQL and most have interfaces to use the bulk unloading/loading tools associated with the major databases.

Yes, SQL can be used to extract the data in most cases. Some legacy systems could require custom programs.

I have worked on DW projects in the past which did not use an external ETL tool. Instead, the load utility was used to extract the data and populate tables which mimic the flat file structure. From that point on, Transact SQL (or PL/SQL or DB2/SQL) can be used to transform and load the staging and production tables.

I am not aware of any attempt to unify ETL tools through industry standards.

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Sometimes the grass is greener on the other side because there is more manure there !

 

[monsky]

Speaking of unifying ETL tools through industry standards from what I've heard OMG is trying to develop a centralized metadata standard that will allow different vendor applications to work together. Let's see what happens...

I haven't really worked with ETL tools although I've seen some of them. My experience was developing my own through VB or FoxPro to extract and transform then generate flatfiles. I developed a data warehouse in Oracle so I just utilized SQL*Loader to do my bulk loads into the data warehouse.