Average-case complexity for the execution of recursive definitions on relational databases

De la Vega, WF; Paschos, VT; Stafylopatis, AN

dc.contributor.author	De la Vega, WF	en
dc.contributor.author	Paschos, VT	en
dc.contributor.author	Stafylopatis, AN	en
dc.date.accessioned	2014-03-01T01:13:36Z
dc.date.available	2014-03-01T01:13:36Z
dc.date.issued	1998	en
dc.identifier.issn	0001-5903	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/12601
dc.subject	Database Query	en
dc.subject	Query Evaluation	en
dc.subject	Relational Database	en
dc.subject.classification	Computer Science, Information Systems	en
dc.subject.other	DEDUCTIVE DATABASES	en
dc.subject.other	QUERIES	en
dc.title	Average-case complexity for the execution of recursive definitions on relational databases	en
heal.type	journalArticle	en
heal.identifier.primary	10.1007/s002360050119	en
heal.identifier.secondary	http://dx.doi.org/10.1007/s002360050119	en
heal.language	English	en
heal.publicationDate	1998	en
heal.abstract	The execution costs of various types of database queries, expressed in terms of linear recusive definitions, are evaluated for two common query evaluation algorithms in the case where the database relations are represented by forests of labelled oriented trees. In a first stage, the execution costs are computed for a given forest. A key issue in this computation is the partition of the set of nodes in the forest into equivalence classes, the properties of which are explored. Moreover, the representation adopted is conceptually simple and provides additional results which are of interest by themselves. In a second stage, the averages of these costs, computed over all databases representable by forests with a given number of nodes, are also evaluated. Finally, the execution cost of the considered database queries is computed for the case where the underlined database relations are modelled as Hamiltonian digraphs.	en
heal.publisher	SPRINGER VERLAG	en
heal.journalName	Acta Informatica	en
dc.identifier.doi	10.1007/s002360050119	en
dc.identifier.isi	ISI:000072834500002	en
dc.identifier.volume	35	en
dc.identifier.issue	3	en
dc.identifier.spage	211	en
dc.identifier.epage	243	en