Handling Redundancy in Data Integration Redundant data occur often when integration of multiple databases Object identification The same attribute or object may have different names in different databases Derivable data, One attribute may be a derived attribute in another table, e.g. annual revenue Redundant attributes may be able to be detected by correlation analysis and covariance analysis Careful integration of the data from multiple sources may help reduce/ avoid redundancies and inconsistencies and improve mining speed and quality 1313 Handling Redundancy in Data Integration ◼ Redundant data occur often when integration of multiple databases ◼ Object identification: The same attribute or object may have different names in different databases ◼ Derivable data: One attribute may be a “derived” attribute in another table, e.g., annual revenue ◼ Redundant attributes may be able to be detected by correlation analysis and covariance analysis ◼ Careful integration of the data from multiple sources may help reduce/avoid redundancies and inconsistencies and improve mining speed and quality