What is ETL?
Extract, Transform and Load (ETL) refers to the process in data warehousing
that concurrently reads (or extracts) data from source systems; converts (or transforms) the data into the proper format for querying and analysis; and loads it into a data warehouse
, operational data store or data mart
. ETL systems commonly integrate data from multiple applications or systems that may be hosted on separate hardware and managed by different groups or users. ETL is commonly used to assemble a temporary subset of data for ad-hoc reporting, migrate data to new databases or convert database into a new format or type.