Consider a relational table r with sufficient number of records, having attributes A₁, A₂,....., A_n and let 1 $$ \le $$ p $$ \le $$ n. Two queries Q1 and Q2 are given below.

$$Q1: \pi_{A_1, \dots ,A_p} \left(\sigma_{A_p=c}\left(r\right)\right)$$ where is a constant

$$Q2: \pi_{A_1, \dots ,A_p} \left(\sigma_{c_1 \leq A_p \leq c_2}\left(r\right)\right)$$ where c₁ and c₂ are constants

The database can be configured to do ordered indexing on A_p or hashing on A_p. Which of the following statements is TRUE?

Consider a relation table with a single record for each registered student with a single record for each registered student with the following attributes.
$$1.$$ $$Registration$$ $$Num:$$ Unique registration number of each registered student.
$$2.$$ $$UID :$$ Unique identity number, unique at the national level for each cityzen.
$$3.$$ $$BankAccount_Num:$$ Unique account number at the bank. A student can have multiple accounts or joint accounts. This attribute stores the primary account number.
$$4.$$ $$Name:$$ Name of the student
$$5.$$ $$Hostel$$ $$Room:$$ Room number of the hostel.

Which of the following options is INCORRECT?

Which one of the following circuits is NOT equivalent to a $$2$$-input $$XNOR$$ (exclusive NOR) gate

The simplified $$SOP$$ (Sum of product) form of the Boolean expression
$$\left( {P + \overline Q + \overline R } \right).\left( {P + \overline Q + R} \right).\left( {P + Q + \overline R } \right)$$ is