Question 329 Which of the following concurrency protocol ensures both conflict serializability and freedom from deadlock : I. 2-phase locking II. Time phase ordering A Both […]

Question 331 Consider the following relational schemas for a library database : Book (Title, Author, Catalog_no, Publisher, Year, Price) Collection(Title, Author, Catalog_no) with the following functional […]

Question 332 The materialization approach of query evaluation includes (from root to leaf) : A π, ∞, σ B π, σ, ∞ C σ, π, ∞ […]

Question 333 onsider the expression t ε instructor ⋏∃ s ∈ department (t [dept_name] = s [dept_name]) The variables t and s are ______________ respectively. A […]