Extract, load, transform
This article includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations. (November 2015)
Extract, load, transform (ELT) is an alternative to extract, transform, load (ETL) used with data lake implementations. In contrast to ETL, in ELT models the data is not transformed on entry to the data lake, but stored in its original raw format. This enables faster loading times. However, ELT requires sufficient processing power within the data processing engine to carry out the transformation on demand, to return the results in a timely manner. Since the data is not processed on entry to the data lake, the query and schema do not need to be defined a priori (although often the schema will be available during load since many data sources are extracts from databases or similar structured data systems and hence have an associated schema). ELT is a data pipeline model.
Cloud data lake components
Common storage options
- Google Storage (GCS)
- ^ Using Redshift Spectrum to load data pipelines Archived 2021-01-18 at the Wayback Machine Published by deductive.com on January 17, 2018, retrieved on April 3, 2019
- Dull, Tamara, "The Data Lake Debate: Pro is Up First", smartdatacollective.com, March 20, 2015.
ELT: Extract, Load, and Transform A Complete Guide | Astera Software