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

SELECT operation in SQL is equivalent to

A positive edge-triggered D flip-flop is connected to a positive edge-triggered JK flip-flop as follows. The Q output of the D flip-flop is connected to both the J and K inputs of the JK flip-flop, while the Q output of the JK flip-flop is connected to the input of the D flip-flop. Initially, the output of the D flip-flop is set to logic one and the output of the JK flip-flop is cleared. Which one of the following is the bit sequence (including the initial state) generated at the Q output of the JK flip-flop when the flip-flops are connected to a free-running common clock? Assume that J = K = 1 is the toggle mode and J = K = 0 is the state-holding mode of the JK flip-flop. Both the flip-flops have non-zero propagation delays.

Consider the operations

$$f\left( {x,y,z} \right) = X'YZ + XY' + Y'Z'$$ and
$$g\left( {x,y,z} \right) = X'YZ + X'YZ' + XY$$.

Which one of the following is correct?