# Recent activity

1
Consider the following tables $T1$ and $T2.$ ... cascade. In order to delete record $\langle 3, 8 \rangle$ from the table $T1,$ the number of additional records that need to be deleted from table $T1$ is _______
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Consider a $2-$way set associative cache with $256$ blocks and uses $LRU$ replacement. Initially the cache is empty. Conflict misses are those misses which occur due to the contention of multiple blocks for the same cache set. Compulsory misses occur due to first time access ... $10$ times. The number of conflict misses experienced by the cache is _________ .
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A database table $T_1$ has $2000$ records and occupies $80$ disk blocks. Another table $T_2$ has $400$ records and occupies $20$ disk blocks. These two tables have to be joined as per a specified join condition that needs to be evaluated for every pair of records from ... table to be used in outer loop, the number of block accesses required for reading the data are $800000$ $40080$ $32020$ $100$
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how many view equivalent schedules are possible for the Sch given below:
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How many Conflict Serializable and View serializable schedules for the Schedule given below $S:r_1(A),w_1(B),w_1(C),r_2(A),w_2(B),w_2(C)$ To both my answer comes to be 7. Is it correct?
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Which of the following disk scheduling strategies is likely to give the best throughput? Farthest cylinder next Nearest cylinder next First come first served Elevator algorithm
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If $M$ is a square matrix with a zero determinant, which of the following assertion (s) is (are) correct? S1: Each row of $M$ can be represented as a linear combination of the other rows S2: Each column of $M$ can be represented as a linear combination of the other columns S3: $MX = 0$ has a nontrivial solution S4: $M$ has an inverse $S3$ and $S2$ $S1$ and $S4$ $S1$ and $S3$ $S1, S2$ and $S3$
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Relation $R$ has eight attributes $\text{ABCDEFGH}$. Fields of $R$ contain only atomic values. $F$= $\text{{CH→G, A→BC, B→CFH, E→A, F→EG}}$ is a set of functional dependencies $(FDs)$ so that $F^+$ is exactly the set of $FDs$ that hold for $R$. How many candidate keys does the relation $R$ have? $3$ $4$ $5$ $6$
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An instance of a relational scheme $R(A, B, C)$ has distinct values for attribute $A$. Can you conclude that $A$ is a candidate key for $R$?
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Consider three processes, all arriving at time zero, with total execution time of $10$, $20$ and $30$ units, respectively. Each process spends the first $\text{20%}$ of execution time doing I/O, the next $\text{70%}$ of time doing computation, and the last $\text{10%}$ of time doing ... . For what percentage of time does the CPU remain idle? $\text{0%}$ $\text{10.6%}$ $\text{30.0%}$ $\text{89.4%}$
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An ER model of a database consists of entity types $A$ and $B$. These are connected by a relationship $R$ which does not have its own attribute. Under which one of the following conditions, can the relational table for R be merged with that of A? Relationship $R$ is one-to ... the participation of $A$ in $R$ is total Relationship $R$ is many-to-one and the participation of $A$ in $R$ is partial
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Which one of the following is FALSE? User level threads are not scheduled by the kernel. When a user level thread is blocked, all other threads of its process are blocked. Context switching between user level threads is faster than context switching between kernel level threads. Kernel level threads cannot share the code segment.
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Consider the following statements about user level threads and kernel level threads. Which one of the following statements is FALSE? Context switch time is longer for kernel level threads than for user level threads. User level threads do not need any ... threads can be scheduled on different processors in a multi-processor system. Blocking one kernel level thread blocks all related threads.
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The grammar $S\rightarrow AC\mid CB$ $C\rightarrow aCb\mid \epsilon$ $A\rightarrow aA\mid a$ $B\rightarrow Bb\mid b$ generates the language $L=\left \{ a^{i}b^{j}\mid i\neq j \right \}$. In this grammar what is the length of the derivation (number of steps starting from $S$) to generate the string $a^{l}b^{m}$ with $l\neq m$ $\max (l,m) + 2$ $l + m + 2$ $l + m + 3$ $\max (l,m) + 3$
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Fill in the blanks: Semaphore operations are atomic because they are implemented within the OS _________.
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Which of the following devices should get higher priority in assigning interrupts? Hard disk Printer Keyboard Floppy disk
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Decompose this table in BCNF ,decomposition should be lossless and dependency preserving. plz clarify me how to decompose to get a lossless decomposition here.
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The head of a hard disk serves requests following the shortest seek time first (SSTF) policy. What is the maximum cardinality of the request set, so that the head changes its direction after servicing every request if the total number of tracks are $2048$ and the head can start from any track? $9$ $10$ $11$ $12$
1 vote
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which of the following cannot be solved using masters theorem? a) T(n) = 2T(n/2) + n/logn b) T(n) = 2T(n/2) + logn c)T(n)=T(n/2)+logn d) non of these
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Assuming the current disk cylinder to be $50$ and the sequence for the cylinders to be $1, 36, 49, 65, 53, 12, 3, 20, 55, 16, 65$ and $78$ find the sequence of servicing using Shortest seek time first (SSTF) and Elevator disk scheduling policies.
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In a system, there are three types of resources: $E, F$ and $G$. Four processes $P_0$, $P_1$, $P_2$ and $P_3$ ... of $F$ were available The system is not in $safe$ state, but would be $safe$ if one more instance of $G$ were available
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Consider a system with $3$ processes that share $4$ instances of the same resource type. Each process can request a maximum of $K$ instances. Resources can be requested and releases only one at a time. The largest value of $K$ that will always avoid deadlock is ___
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Let the time taken to switch from user mode to kernel mode of execution be $T1$ while time taken to switch between two user processes be $T2$. Which of the following is correct? $T1 > T2$ $T1 = T2$ $T1 < T2$ Nothing can be said about the relation between $T1$ and $T2$
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State True or False with reason There is always a decomposition into Boyce-Codd normal form (BCNF) that is lossless and dependency preserving.
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Consider an instruction pipeline with five stages without any branch prediction: Fetch Instruction (FI), Decode Instruction (DI), Fetch Operand (FO), Execute Instruction (EI) and Write Operand (WO). The stage delays for FI, DI, FO, EI and WO are ... is taken during the execution of this program, the time (in ns) needed to complete the program is $132$ $165$ $176$ $328$
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Consider a two-level cache hierarchy with $L1$ and $L2$ caches. An application incurs $1.4$ memory accesses per instruction on average. For this application, the miss rate of $L1$ cache is $0.1$; the $L2$ cache experiences, on average, $7$ misses per $1000$ instructions. The miss rate of $L2$ expressed correct to two decimal places is ________.
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What is the complexity of the following code? sum=0; for(i=1;i<=n;i*=2) for(j=1;j<=n;j++) sum++; Which of the following is not a valid string? $O(n^2)$ $O(n\log\ n)$ $O(n)$ $O(n\log\ n\log\ n)$
Let $M = (K, Σ, Г, Δ, s, F)$ be a pushdown automaton, where $K = (s, f), F = \{f\}, \Sigma = \{a, b\}, Г = \{a\}$ and $Δ = \{((s, a, \epsilon), (s, a)), ((s, b, \epsilon), (s, a)), (( s, a, a), (f, \epsilon)), ((f, a, a), (f, \epsilon)), ((f, b, a), (f, \epsilon))\}$. Which one of the following strings is not a member of $L(M)$? $aaa$ $aabab$ $baaba$ $bab$
In the given matrix $\begin{bmatrix} 1 & -1 & 2 \\ 0 & 1 & 0 \\ 1 & 2 & 1 \end{bmatrix}$ , one of the eigenvalues is 1. The eigenvectors corresponding to the eigenvalue 1 are $\left\{a\left(4,2,1\right) \mid a \neq 0, a \in \mathbb{R}\right\}$ ... $\left\{a\left(- \sqrt{2},0,1\right) \mid a \neq 0, a \in \mathbb{R}\right\}$
Consider the following C functions: int f1 (int n) { if(n == 0 || n == 1) return n; else return (2 * f1(n-1) + 3 * f1(n-2)); } int f2(int n) { int i; int X[N], Y[N], Z[N]; X[0] = Y[0] = Z[0] = 0; X[1] = 1; Y[1] = 2; Z[1] = 3; for(i = 2; i <= n; i++){ X ... $f1(n)$ and $f2(n)$ are $\Theta(n)$ and $\Theta(n)$ $\Theta(2^n)$ and $\Theta(n)$ $\Theta(n)$ and $\Theta(2^n)$ $\Theta(2^n)$ and $\Theta(2^n)$