Masum Kazi

  Question: Which of the following is the key of a relation schema R = (M, N, O, P, S, T), when R has the functional dependencies shown below?    O → T  S → M  OS → P  M → N  a) MO           b) MS         c) OP         d) OS Explanation:  To determine the key of the relation schema R = ( M , N , O , P , S , T )  given the functional dependencies, we need to figure out the minimal set of attributes that can determine all the attributes of the relation. This minimal set is the candidate key . Functional Dependencies: O → T O S → M S   O S → P OS M → N M  Step 1: Identify which attributes can be derived From O → T , if we have O , we can determine T . From S → M , if we have S , we can determine M . From M → N , if we know M , we can determine N . From O S → P , if we know both O and S , we can determine P . Step 2: Determine the closure of attri...

 Which of the following is the pre-order traversal of the tree below? Explanation: Pre-order traversal of a tree is a type of depth-first traversal where the nodes of the tree are visited in the following order: Visit the root node first . Traverse the left subtree recursively using pre-order. Traverse the right subtree recursively using pre-order. In simple terms, the pre-order traversal visits the root before its child nodes. The general process is summarized as: Root → Left → Right Example: Consider the following binary tree: 1 / \ 2 3 / \ 4 5 The pre-order traversal would visit the nodes in this order: 1 → 2 → 4 → 5 → 3

The operations for a queue are defined as below.   ENQ n: This operation appends data n to the queue.   DEQ: This operation removes data from the queue.   On an empty queue, the operations ENQ 1, ENQ 2, ENQ 3, DEQ, ENQ 4, ENQ 5, DEQ, ENQ 6, DEQ, DEQ are performed. After that, when DEQ is performed, what is the value that is removed? Explanation: Let's walk through the operations step by step on an empty queue. ENQ 1 : Queue = [1] ENQ 2 : Queue = [1, 2] ENQ 3 : Queue = [1, 2, 3] DEQ : Removes 1 → Queue = [2, 3] ENQ 4 : Queue = [2, 3, 4] ENQ 5 : Queue = [2, 3, 4, 5] DEQ : Removes 2 → Queue = [3, 4, 5] ENQ 6 : Queue = [3, 4, 5, 6] DEQ : Removes 3 → Queue = [4, 5, 6] DEQ : Removes 4 → Queue = [5, 6] Now, when the next DEQ is performed, the value that is removed is 5 . So, the value removed by the next DEQ is 5 .

 A five-digit number a1 a2 a3 a4 a5 needs to be stored in an array by means of hashing. When the hash function is mod (a1+a2+a3+a4+a5, 13) and the number is stored in the array element at the position corresponding to the calculated hash value, which of the following is the position where 54321 is stored in the array? Here, the value of mod (x, 13) is the remainder after dividing x by 13 Explanation:  We need to calculate the position in the array where the number 54321 is stored using the given hash function: The number is 54321 , which has digits: a 1 = 5 a_1 = 5 a 2 = 4 a_2 = 4 a 3 = 3 a_3 = 3 a 4 = 2 a_4 = 2 a 5 = 1 a_5 = 1 The hash function is defined as: hash = m o d     ( a 1 + a 2 + a 3 + a 4 + a 5 , 13 ) \text{hash} = \mod(a_1 + a_2 + a_3 + a_4 + a_5, 13) Step 1: Sum of the digits a 1 + a 2 + a 3 + a 4 + a 5 = 5 + 4 + 3 + 2 + 1 = 15 a_1 + a_2 + a_3 + a_4 + a_5 = 5 + 4 + 3 + 2 + 1 = 15 Step 2: Calculate the hash value hash = m o d     ( 15 , 13 ) \text{hash} = \mo...

Which of the following is a program that achieves dynamic processing in a web? a) JavaScript b) Java applet c) Java servlet d) VBScript Answare: c Explanation: JavaScript : Runs on the client-side (in the browser), not just on the server. Java applet : Runs on the client-side (in the browser with a Java plugin), though not commonly used anymore. Java servlet : A server-side program that runs on the web server to handle dynamic processing (e.g., generating dynamic web content). VBScript : Primarily a client-side scripting language (although it can be used server-side with ASP, it's not as common as Java servlets for server-side operations).