Estimating the quality of data in relational databases(4)

Finally,inSection5,wedescribetheprocessofinferringthequalityofanswerstoarbi-traryqueriesfromthequalityspeci cationsthathavebeenassignedtothedatabase.Ourtreatmentoftheproblemisinthecontextofrelationaldatabases,andweassumethestandardde nitionsoftherelationalmodel[17].Inparticular,thedatabasecomponentsmentionedearlierarede nedusingthemechanismofviews.Wealsomakethefollowingassumptions.

1.Queriesandviewsuseonlytheprojection,selection,andCartesianproductoperations,selectionsuseonlyrangeconditions,andprojectionsalwaysretainthekeyattribute(s).

2.Thestoredinformation(thedatabaseinstances)arerelativelystatic,andhencethequalityofdatadoesnotchangefrequently.

Becauseofspacelimitations,severalkeyissuesandsolutionsareonlysketchedinthispaper,andfullerdiscussionsareprovidedin[11].

搜索“diyifanwen.net”或“第一范文网”即可找到本站免费阅读全部范文。收藏本站方便下次阅读，第一范文网，提供最新人文社科Estimating the quality of data in relational databases(4)全文阅读和word下载服务。