TY - GEN
T1 - Queries with incomplete answers over semistructured data
AU - Kanza, Yaron
AU - Nutt, Werner
AU - Sagiv, Yehoshua
PY - 1999
Y1 - 1999
N2 - The principles of queries that allow incomplete answers are presented. Partial answers make it necessary to refine the model of query evaluation. The first modification relates to the satisfaction of conditions, under some circumstances, conditions involving unbound variables as satisfied are considered. Second, in order to prevent a proliferation of answers, only answers that are maximal in the sense that there are no assignments that bind more variables and satisfy the conditions of the query, are accepted. The mode of query evaluation consists of two phases, a search phase and a filter phase. The containment problem for queries consisting only of search constraints under the different semantics are investigated.
AB - The principles of queries that allow incomplete answers are presented. Partial answers make it necessary to refine the model of query evaluation. The first modification relates to the satisfaction of conditions, under some circumstances, conditions involving unbound variables as satisfied are considered. Second, in order to prevent a proliferation of answers, only answers that are maximal in the sense that there are no assignments that bind more variables and satisfy the conditions of the query, are accepted. The mode of query evaluation consists of two phases, a search phase and a filter phase. The containment problem for queries consisting only of search constraints under the different semantics are investigated.
UR - https://www.scopus.com/pages/publications/0032638571
U2 - 10.1145/303976.303999
DO - 10.1145/303976.303999
M3 - ???researchoutput.researchoutputtypes.contributiontobookanthology.conference???
AN - SCOPUS:0032638571
SN - 1581130627
T3 - Proceedings of the ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems
SP - 227
EP - 236
BT - Proceedings of the 18th ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems, PODS 1999
PB - ACM Transactions on Intelligent Systems and Technology
T2 - 18th ACM SIGMOD-SIGACT-SIGART Symposium on Principles of Database Systems, PODS 1999
Y2 - 31 May 1999 through 3 June 1999
ER -