Originally posted by st2000 ..but can anyone show me in code what ETL is
ETL is not something one can show "in" code as you have put. ETL is a concept of transforming data (generally OLTP data or Flat File data) that adheres to a Data Warehouse Model.
Using Tools to achive this is easiest, specially "Informatica". If you don't want to use any tools, you can write PL/SQL Stored Procedures and tranform and load the data. It depends what your "transformation logic" is, which is derived from your business requirements.
Since your fundas doesn't seem clear enough, I suggest you start looking into basic Data Warehosuing concepts..you will get plenty of material if you search on Google.
Originally posted by st2000 Hi.. I want to know how ETL works.. I have read a few articles etc., but can anyone show me in code what ETL is.. There could be many tools, but I want to know how it is done manually..
Identify a table, extract to flatfiles, transform and load..
If anyone can point me to the right place on the web that's fine too..
ETL as such is a concept......as quester said.....
Informatica is a ETL tool & the code of which u cant get......
Even if u get by any chance( If u know the guys who have developed )
i dont think u will be able to digest it....
"I Dont Want To Follow A Path, I would Rather Go Where There Is No Path And Leave A Trail."
"Ego is the worst thing many have, try to overcome it & you will be the best, if not good, person on this earth"
it's slow, full of idiotic "quirks", it doesn't maintain reliable dependencies, it is very very expensive, there are a great many useful Oracle features that just can't be supported using it (merge, insert /*+ append */ , bulk updates, insert into .. returning etc.), it's a bastard to debug a complex mapping blah blah blah. The metadata reporting functionality is abysmal -- it's there as a marketing tool only, according to informatica tech staff.
I've been using it for over four years now, and i dislike it more and more.