Introduction to ETL

1, the definition of ETL

ETL is "Extract"," Transform","Load" the initials of three words namely "extract "," Conversion "," Loading ", but we are often referred to as the daily data extraction.

ETL is the core and soul of BI/DW (Business intelligence/Data Warehouse), integrating and improving the value of data according to the unified Rules , is responsible for the completion of data from the data source to the target data Warehouse conversion process, is an important step in implementing a data warehouse.

The ETL contains three aspects:

extract : Read the data from a variety of original business systems, which is the premise of all work.

" conversion ": According to the pre-designed rules will be extracted data conversion, so that the original heterogeneous data format can be unified together.

Mount : Imports the converted data into the Data Warehouse on a schedule, incrementally, or all.

2, why need ETL?

Because the application system currently running is an irreplaceable system that the user spends a lot of energy and money to build, especially the data in the system is very valuable. However, due to the different source and format of the data in the original database, the system implementation and data integration problems are caused . ETL is used to solve this problem.

Introduction to ETL