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Questions tagged [etl]

'Extract, Transform and Load': Data load processing, normally in the context of data warehouse systems.

ETL (Extract, Transform and Load) processing is used to load a database from an external source. Normally used in the context of data warehouse systems, an ETL process has the three eponymous functions

  • Extract: data is extracted from the source system. The source could be a database, file, or API exposed by the source system.

  • Transform: The data from the source system may not be in the same format as the destination. Transformation is the process of changing the data so it will load correctly into the destination.

  • Load: The data is loaded into the destination, often through some sort of bulk load facility.

ETL processing can be done with hand-built code in SQL or a client-side language, or it can be done with tools specifically designed for the job (usually referred to as 'ETL tools'). Examples of such tools include SQL Server Integration Services and Informatica Powercentre.

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Any Open Source / free ETL out there?

I was using Pentaho Data Integration even before Pentaho bought it and call it that. I have the last free version. I went on their website recently to see if they had released another version only to find out my favorite open source etl is not much…
Nicolas de Fontenay
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How can I use an ETL?

I know that those letters mean Extract, Transform, and Load. But, when I used it at first, I thought that during the Transform phase I could do plenty of different joins on data that I've extracted from data sources, later on I realized that doing a…
Spredzy
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Does ELT data end up in an RDBMS?

I think I am confusing things. In ETL, data conversion starts at Database A and ends up in Database B, both are relational databases. Maybe I have a 20-year-old system. I use ETL to get the data between the two databases. I do not know what else…
johnny
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General ETL principle - ETL from unknown number of tables?

AFAIK, ETL integrates data from a fixed number of sources/tables. Is it possible that ETL can integrate data from an unknown number of tables which might be added in the future, given that these tables might be of different types (customer,…
Steam
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I need explaination about Develop Detailed Table Schematics In Step 4, Chapter 20, The Data Warehouse Toolkit, 3rd Edition

Have anyone read The Data Warehouse Toolkit, 3rd Edition written by Ralph Kimball and his colleagues? I signed up for a Data Warehouse course at my uni and my prof told me and my group to read Chapter 20 and summaries to him. I've struggled to…
silverbullet069
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