Data Marts
* Dependent DM* Independent DM Database Design
* Star Schema
* Fact Constellation Schema SCD (Slowly Changing Dimensions)
* TYPE1SCD
* TYPE2SCD
* TYPE3SCD Basic concepts in SQL
ETL is commonly associated with Data Warehousing projects but there in reality any form of bulk data movement from a source to a target can be considered ETL. Large enterprises often have a need to move application data from one source to another for data integration or data migration purposes. ETL testing is a data-centric testing process to validate that the data has been transformed and loaded into the target as expected.
Difference between OLTP and Data Warehousing
* Data Extraction
* Data Transformation
* Data Loading
* MINUS Query
* COUNT Query