The description and optimization of query are proposed for advanced data query in process industrial data model . the method is easy to be realized . 3 對(duì)于流程工業(yè)數(shù)據(jù)的高級(jí)查詢提出了一種查詢表示和查詢優(yōu)化的方法,這種方法易于實(shí)現(xiàn)并且具有很高的效率。
2 . the characteristics of process industrial real - time database model are introduced and a process industrial data model is built which adopts tags mapping method . the data model can handle the tag computation , lab ' s tag definition and process parameter store 2 )根據(jù)流程工業(yè)實(shí)時(shí)數(shù)據(jù)庫(kù)的應(yīng)用背景,提出了以位號(hào)映射為特點(diǎn)的工程數(shù)據(jù)模型,這種模型支持位號(hào)間的計(jì)算關(guān)系,支持錄入功能和計(jì)算參數(shù)存儲(chǔ)。