Data Warehouse, data quality is the single most important thing as the poor quality can impact organization decision capabilities. The Data quality has to be defined during the initial stages of the application design when ETL requirements for operational systems are developed and has to be managed throughout the application development, use and maintenance stages of the project.
Data profiling typically takes place at the beginning of the design and development process of integrating systems.Source data collection can be analyzed and the metadata including data rules available about these data can be corrected and completed. As a result of data profiling step,data quality rules are defined which can then be monitored during the ETL processes. Data quality issues found during ETL can be corrected in two ways; providing applications to correct data offline and generating data quality reports to quality issue management to take the necessary actions.