On Query Containment Problem for Conjunctive Queries Under Bag- Set Semantics
| Title: On Query Containment Problem for Conjunctive Queries Under Bag- Set Semantics |
| Author: Victor Felea, Violeta Falea |
| Abstract: The query containment is one of the fundamental problems in the context of query processing and optimization. Concerning the answer of queries for databases, three semantics were intensively analyzed. In the first one, called set, both databases and answer of queries for databases are considered sets. In the second one, called bag-set databases are sets, but the answer are bags ( multi-sets ). In the third one, called bag, both databases and answer are bags. In this paper, we study the query containment problem for conjunctive queries ( CQs ) under bag-set semantics. It is not known whether this problem is decidable. We give a characterization of this problem. |
| Keywords: Conjuctive queries Qiery containment Bag-set semantics |
| Corresponding Author: |
| Download: Intelligent Information and Database Systems |
