Querying complex objects by similarity in SQL Maria Camila Nardini Barioni, Humberto Luiz Razente, Caetano Traina Jr., and Agma J. M. Traina   View Paper (PDF)   Return to Consultas e Visões/Queries and Views Abstract Similarity search has received large attention on modern database applications involving complex objects, since the queries executed in such databases are seldom based on exact matches but rather on some specific notion of similarity. However, the SQL query language does not provide effective support for similarity queries. This paper proposes the addition of similarity queries to SQL, including a new set of similarity operators in order to search complex objects stored as sets of attributes in a relation. It also describes a prototype developed to validate and illustrate the concepts and syntax presented. ©2006 Association for Computing Machinery