How many rules are there in Codd's RDBMS concepts?

Which type of key is used for the Referential Integrity Constraint?

Which one of the following is NOT a part of the ACID properties of database transactions?

The _______ statement makes the updates performed by the transaction permanent.

A file is organized so that the ordering of data records is the same as or close to the ordering of data entries in some index. Then that index is called

Suppose the following functional dependencies hold on a relation U with attributes P, Q, R, S and T:

P → QR

RS → T

Which of the following functional dependencies can be inferred from the above functional dependencies?

A relation r(A,B) in a relational database has 1200 tuples. The attribute A has integer values ranging from 6 to 20, and the attribute B has integer values ranging from 1 to 20. Assume that the attributes A and B are independently distributed. The estimated number of tuples in the output of σ_{(A>10)∨(B=18)}(r)

Choose the correct statement regarding superkeys.

Consider a linear list based directory implementation in a file system. Each directory is a list of nodes, where each node contains the file name along with the file metadata, such as the list of pointers to the data blocks. Consider a given directory foo. Which of the following operations will necessarily require a full scan of foo for successful completion?

1. Creation of a new file in foo
2. Deletion of an existing file from foo
3. Renaming of an existing file in foo
4. Opening of an existing file in foo

Consider the following two phase locking protocol. Suppose a transaction T accesses (for read or write operations), a certain set of objects {O1,...,Ok}. This is done in the following manner: Step 1. T acquires exclusive locks to O1, . . . , Ok in increasing order of their addresses. Step 2. The required operations are performed. Step 3. All locks are released. This protocol will