A computer-based technique is provided for retrieving one or more items from a database in response to a query specified by a user via one or more example sets. Preferably the example sets include multiple positive and negative example sets. The method comprises the following steps. First, a scoring function is constructed from the one or more example sets. The scoring function gives higher scores to database items that are more closely related to the query than to database items that are not as closely related to the query. The scoring function is operable for use with a multidimensional indexing structure associated with the database. Then, the one or more database items that have the highest score as computed using the scoring function are retrieved via the multidimensional indexing structure.