... to the original one. This question was addressed in the literature with respect to those relational schemes that satisfy the so ... \"tractable\" We are able to test losslessness defined in such a way for a wide class of relational expressions and dependencies. An ...
Publication - huliganka - 04/17/2013 - 00:27 - 0 comments - 1 attachment
... A subtle problem of schema integration is considered in its general form, not bound to any particular category of schemas. The ... theory are established that apply to integrity problems in schema integration. The theory is illustrated by a particular category of ...
Publication - huliganka - 04/16/2013 - 19:27 - 0 comments - 1 attachment
... 676.21 KB In this article, we develop a relational algebra for metadata integration, ... where the number of relations and/or the number of columns in relations of the output varies dynamically with the input instance. Among ... generalized dynamic output schemas, where the values in any (fixed) number of input columns can determine output schemas.Further ...
Publication - cat - 04/16/2013 - 18:27 - 0 comments - 1 attachment
... parts of a given data collection play an important role in many database applications. In dynamic environments where data is updated, not only information provided by ...
Publication - cat - 04/16/2013 - 18:16 - 0 comments - 1 attachment
Authors: Larson, J. A.; Navathe, S. B.; Elmasri, R. Author: Larson, J ...
Publication - admin - 04/16/2013 - 15:16 - 0 comments - 1 attachment
... two groups of relation schemata play important roles in a database environment. These transformations are used for obtaining normal ... belonging to one group of schemata are usually maintained in computer storage, while those belonging to another group of schemata can be ...
Publication - cat - 04/15/2013 - 20:27 - 0 comments - 1 attachment
