Abstract: A method for identifying joined rows in a database comprising a plurality of tables. The method comprises selecting a group of tables directly or indirectly joined with each other, selecting an order of the group based on relationships among the tables, generating an intermediate data structure which identifies the group of tables, a number of virtual tables equal to one less than the number of tables in the group, and an indication of an adjacent table, and a common table and key for at least some of the group of tables and the virtual tables, generating indexing data structures for the group of tables and virtual tables, and, inserting information from rows of the group of tables into the indexing data structures using the intermediate data structure. The indexing data structure for one virtual table indicates which of the rows of the tables have common data elements.

Abstract: A deformable mirror element with a high natural frequency has elongate ribbons attached along a longitudinal portion thereof to a support. A reflective wing portion extends laterally from the support and is capable of deforming in response to a force applied to the wing. The deformable mirror element is used in a light valve for modulating one or more beams of light. The high natural frequency of the element ensures that the light valve is useful in applications requiring fast response time.