懒惰人民 发表于 2025-3-28 17:00:31
Generalized relational algebra: Modeling spatial queries in constraint databases,om the one proposed in , and a family of generalized relational algebra languages, derived from the language proposed in and in . Each language of the family is obtained by specifying a certain logical theory for constraints and a particular application domain, by means of a set of func荧光 发表于 2025-3-28 18:44:27
http://reply.papertrans.cn/24/2360/235923/235923_42.png角斗士 发表于 2025-3-29 01:54:33
http://reply.papertrans.cn/24/2360/235923/235923_43.pngdictator 发表于 2025-3-29 05:53:56
The application of multi-dimensional indexing methods to constraints, satisfy all the constraints of the problem. The art of constraint programming is to find ways of narrowing down the search space as much as possible with as little computational effort as possible. In databases, this is what indexes are for. And yet surprisingly little effort has so far been devoteCONE 发表于 2025-3-29 08:52:20
Towards the definition of a spatial object-oriented data model with constraints, and Kornatzky. We augment Brodsky and Kornatzky‘s model with a few simple primitives, that would make querying the model simpler and more natural. Our basic model is quite similar to the Brodsky and Kornatzky‘s model but, by the introduction of the notion of a ., the modelling of part-subpart relatNOTCH 发表于 2025-3-29 13:44:13
Ambiguity for referential integrity is undecidable,rity constraints is now included in the new SQL2 standard with capabilities to react on violations of specified integrity constraints. These reactions may lead to indeterminism with respect to the outcome of a user operation which is also known from the usage of rules or triggers. In the databa