Which is true about invalid PL/SQL objects?
A)They are automatically recompiled against the new definition of a referenced object when they are called.
B)They must be manually recompiled before they can be used if a DDL is performed on a table that is referenced in the PL/SQL object.
C)They are automatically recompiled against the new definition of a referenced object at the same time as the referenced object is modified.
D)They can be manually recompiled only by using SQL commands.
Answer: A
趙：
A 譯：它們在被調用時根據引用對象的新定義自動重新編譯。
B 譯：如果在 PL/SQL 對象中引用的表上執行 DDL，則必須手動重新編譯它們才能使用它們。