TY - GEN
T1 - Revisiting redundancy and minimization in an XPath fragment
AU - Kimelfeld, Benny
AU - Sagiv, Yehoshua
PY - 2008
Y1 - 2008
N2 - Redundancy and minimization of queries are investigated in a well known fragment of XPath that includes child and descendant edges, branches, wildcards, and multiple output nodes. Contrary to a published result, a proposed technique does not guarantee minimality or even non-redundancy, and it is unknown whether a non-redundant query is also minimal. It is shown that for two sub-fragments, non-redundancy and minimality are the same, and can be realized by means of simple (local) tests. The latter property is used to prove that testing non-redundancy is NP-complete.
AB - Redundancy and minimization of queries are investigated in a well known fragment of XPath that includes child and descendant edges, branches, wildcards, and multiple output nodes. Contrary to a published result, a proposed technique does not guarantee minimality or even non-redundancy, and it is unknown whether a non-redundant query is also minimal. It is shown that for two sub-fragments, non-redundancy and minimality are the same, and can be realized by means of simple (local) tests. The latter property is used to prove that testing non-redundancy is NP-complete.
UR - http://www.scopus.com/inward/record.url?scp=43349087909&partnerID=8YFLogxK
U2 - 10.1145/1353343.1353355
DO - 10.1145/1353343.1353355
M3 - ???researchoutput.researchoutputtypes.contributiontobookanthology.conference???
AN - SCOPUS:43349087909
SN - 9781595939265
T3 - Advances in Database Technology - EDBT 2008 - 11th International Conference on Extending Database Technology, Proceedings
SP - 61
EP - 72
BT - Advances in Database Technology - EDBT 2008 - 11th International Conference on Extending Database Technology, Proceedings
T2 - 11th International Conference on Extending Database Technology, EDBT 2008
Y2 - 25 March 2008 through 29 March 2008
ER -