A.48%~51% B.49%~52% C.49%~51% D.48%~52%
A.死區(qū)壓縮、平行四邊形壓縮 B.平行四邊形壓縮、斜率壓縮 C.回程壓縮、斜率壓縮 D.死區(qū)壓縮、回程壓縮
A.定義數(shù)據(jù)庫,包括歷史數(shù)據(jù)和實(shí)時數(shù)據(jù) B.實(shí)時數(shù)據(jù)庫指現(xiàn)場物理I/O點(diǎn)數(shù)據(jù)和控制計(jì)算時中間變量點(diǎn)的數(shù)據(jù) C.歷史數(shù)據(jù)庫是按一定的存儲周期存儲的實(shí)時數(shù)據(jù),通常將數(shù)據(jù)存儲在硬盤上或刻錄在光盤上,以備查用 D.定義歷史數(shù)據(jù)和實(shí)時數(shù)據(jù)的趨勢顯示、列表及打印輸出等