ETL Tools

ETL TOOLS

The times of increasing data-dependence forced a lot of companies to invest in complicated data warehousing systems. Their differentiation and incompatibility led to an uncontrolled growth of costs and time needed to coordinate all the processes. The ETL (Extract, transform, load) tools were created to simplify the data management with simultaneous reduction of absorbed effort. 

Depending on the needs of customers there are several types of tools. 
One of them perform and supervise only selected stages of the ETL process like data migration tools(EtL Tools , “small t”tools) , data transformation tools(eTl Tools , “capital T”tools).Another are complete (ETL Tools ) and have many functions that are intended for processing large amounts of data or more complicated ETL projects. 

Some of them like server engine tools execute many ETL steps at the same time from more than one developer , while other like client engine tools are simpler and execute ETL routines on the same machine as they are developed. 
There are two more types. First called code base tools is a family of programing tools which allow you to work with many operating systems and programing languages.The second one called GUI base tools remove the coding layer and allow you to work without any knowledge (in theory) about coding languages.

How do the ETL tools work ? |ETL Tools Selection in Data Warehousing

How do the ETL tools work?

The first task is data extraction from internal or external sources. After sending queries to the source system data may go indirectly to the database. However usually there is a need to monitor or gather more information and then go to Staging Area . Some tools extract only new or changed information automatically so we dont have to update it by our own. 
The second task is transformation which is a broad category: 
-transforming data into a stucture wich is required to continue the operation (extracted data has usually a sructure typicall to the source) 
-sorting data 
-connecting or separating 
-cleansing 
-checking quality 

The third task is loading into a data warehouse. 

As you can see the ETL Tools have many other capabilities (next to the main three: extraction , transformation and loading) like for instance sorting , filtering , data profiling , quality control, cleansing , monitoring , synchronization and consolidation.