ETL Concepts: Extraction, transformation, and loading. ETL refers to the methods involved in accessing and manipulating source data and loading it into target database. The first step in ETL process is mapping the data between source systems and target database(data warehouse or data mart). The second step is cleansing of source data in staging area….
Database – RDBMS: There are a number of relational databases to store data. A relational database contains normalized data stored in tables. Tables contain records and columns. RDBMS makes it easy to work with individual records. Each row contains a unique instance of data for the categories defined by the columns. RDBMS are used in…
What is a Data Warehouse? According to Inmon, famous author for several data warehouse books, “A data warehouse is a subject oriented, integrated, time variant, non volatile collection of data in support of management’s decision making process”. In order to store data, over the years, many application designers in each branch have made their individual decisions…
