傳統(tǒng)的關(guān)系模式只能處理一些確定性的信息，而在現(xiàn)實生活當(dāng)中大量存在著不確定
的信息，而傳統(tǒng)的關(guān)系模式對這些信息是不能進(jìn)行有效處理的。本文在總結(jié)有關(guān)研究工作的基礎(chǔ)上，提出了一種能夠存儲不確定性信息的數(shù)據(jù)庫模型——概率關(guān)系數(shù)據(jù)庫模型，并給出了概率關(guān)系的查詢運(yùn)算，包括單表查詢和多表連接查詢。
關(guān)鍵詞：概率關(guān)系代數(shù)；概率數(shù)據(jù)庫；概率查詢
Abstract: Traditional relation model can only process some certain information, while in our
daily life, there are so many uncertain information, but it can not be processed by the traditional relation model. Under some research in the relational area, a new database model——probabilistic relation database model is introduced and it can process uncertain information. At last this paper gives query operation in probabilistic database including single table query and multi-table join query.
Keywords: probabilistic relation algebra; probabilistic database；probabilistic query