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已知關聯( relation) T( A, B, C, D, E, F), 其函數相依集( functional dependency set) F = {B → D, C → A, AD → F}, 下列何者為T 之無損分解( lossless decomposition) ? ( A) T1 = {A, B, C, D}, T2 = {A, D, E, F} ( B) T1 = {A, B, C, F}, T2 = {B, C, D, E} ( C) T1 = {A, C, D, F}, T2 = {B, C, E, F} ( D) T1 = {A, D, E, F}, T2 = {B, C, D, F} 請問要怎分解? 我的想法 B->D C->A 可分為CD->AD AD->F CD->AD->F 等於 CD->F Orz -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 218.172.91.9