Query Optimizer for the ETL Process in Data Warehouses
Bhadresh Pandya, Sanket Shah · Zenodo (CERN European Organization for Nuclear Research) · 2015
ETL (Extraction-Transformation-Loading) process is responsible for extracting data from several sources, cleansing, transforming, integrating and loading into a data warehouse. Extraction process accesses large amount of data by executing several complex queries in source databases. These queries are repetitive and executed at regular interval to refresh the data warehouse. Extraction of data from source must be completed in a certain time window; hence it is necessary to optimize its execution time. In this paper, we delve into the optimization of queries by recommending indices which reduces cost of the queries and improves performance of the queries.