Databases: GATE CS previous year questions, 2011 to 2026

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All Databases questions

GATE CS 2026 Set 1MSQ1 markEasy (estimate)
GATE CS 2026 Set 1, Q.30
Let $P, Q, R$ and $S$ be the attributes of a relation in a relational schema. Let $X ⟶ Y$ indicate functional dependency in the context of a relational database, w...
Functional Dependencies and Normalization
GATE CS 2026 Set 1MSQ1 markEasy (estimate)
GATE CS 2026 Set 1, Q.31
In the context of relational database normalization, which of the following statements is/are true?
Functional Dependencies and Normalization
GATE CS 2026 Set 1MCQ2 marksEasy (estimate)
GATE CS 2026 Set 1, Q.43
Consider a relational database schema with two relations $R (P, Q)$ and $S (X, Y)$ . Let…
Relational Algebra and Tuple Relational Calculus
GATE CS 2026 Set 1NAT2 marksEasy (estimate)
GATE CS 2026 Set 1, Q.65
Consider a relational database schema with a relation $R (A, B, C, D)$ . If ${A, B}$ and ${A, C}$ are the only two candidate keys of the relation $R$ , then the number of super...
Functional Dependencies and Normalization
GATE CS 2026 Set 2MCQ1 markEasy (estimate)
GATE CS 2026 Set 2, Q.15
In the context of DBMS, consider the two sets T and S given below. T S I: Logical schema L: Views II: Physical schema M: File organization and indexes III: External schema N: Re...
ER Model and Relational Schema Design
GATE CS 2026 Set 2MCQ1 markEasy (estimate)
GATE CS 2026 Set 2, Q.20
Consider concurrent execution of two transactions $T_{1}$ and $T_{2}$ in a DBMS, both of which access a data object $A$ . For these two transactions to not conflict on $A$ , which one...
Transactions, Serializability and Concurrency Control
GATE CS 2026 Set 2MCQ2 marksEasy (estimate)
GATE CS 2026 Set 2, Q.42
In the context of schema normalization in relational DBMS, consider a set F of functional dependencies. The set of all functional dependencies implied by F is called the closure...
Functional Dependencies and Normalization
GATE CS 2026 Set 2MCQ2 marksEasy (estimate)
GATE CS 2026 Set 2, Q.46
An index in a DBMS is said to be dense if an index entry appears for every search-key value in the indexed file. Otherwise it is called a sparse index. Consider the following tw...
File Organization, B-Trees and B+ Trees Indexing
GATE CS 2025 Set 1MCQ1 markEasy (estimate)
GATE CS 2025 Set 1, Q.15
A schedule of three database transactions $T_{1}$ , $T_{2}$ , and $T_{3}$ is shown. $R_{i} (A)$ and $W_{i} (A)$ denote read and write of data item $A$ by transaction $T_{i}$ , $i = 1, 2, 3$ . The...
Transactions, Serializability and Concurrency Control
GATE CS 2025 Set 1MSQ1 markMedium (estimate)
GATE CS 2025 Set 1, Q.21
Consider the following $B^{+}$ tree with 5 nodes, in which a node can store at most 3 key values. The value $23$ is now inserted in the $B^{+}$ tree. Which of the following options(...
File Organization, B-Trees and B+ Trees Indexing
GATE CS 2025 Set 1MCQ2 marksEasy (estimate)
GATE CS 2025 Set 1, Q.39
Consider two relations describing $teams$ and $players$ in a sports league: $teams (tid, tname)$ : $tid, tname$ are...
Relational Algebra and Tuple Relational Calculus
GATE CS 2025 Set 1MSQ2 marksEasy (estimate)
GATE CS 2025 Set 1, Q.47
Consider a relational schema $team (name, city, owner)$ , with functional dependencies…
Functional Dependencies and Normalization
GATE CS 2025 Set 1NAT2 marksEasy (estimate)
GATE CS 2025 Set 1, Q.55
Consider the following database tables of a sports league. player(pid,pname,age) coach(cid,cname) team(tid,tname,city,cid) members(pid,tid) An instance of the table and...
SQL Queries and Integrity Constraints
GATE CS 2025 Set 2MSQ1 markEasy (estimate)
GATE CS 2025 Set 2, Q.27
An audit of a banking transactions system has found that on an earlier occasion, two joint holders of account $A$ attempted simultaneous transfers of Rs. 10000 each from account...
Transactions, Serializability and Concurrency Control
GATE CS 2025 Set 2MSQ2 marksMedium (estimate)
GATE CS 2025 Set 2, Q.46
Consider the following relational schema along with all the functional dependencies that hold on them.…
Functional Dependencies and Normalization
GATE CS 2025 Set 2MSQ2 marksEasy (estimate)
GATE CS 2025 Set 2, Q.53
Consider the database transactions T1 and T2, and data items X and Y. Which of the schedule(s) is/are conflict serializable? Transaction T1 Transaction T2 R1(X) W2(X) W1(Y) W2(Y...
Transactions, Serializability and Concurrency Control
GATE CS 2025 Set 2MSQ2 marksEasy (estimate)
GATE CS 2025 Set 2, Q.54
Consider the following relational schema: Students (rollno: integer, name: string, age: integer, cgpa: real) Courses (courseno: integer, cname: string, credits: integer)…
SQL Queries and Integrity Constraints
GATE CS 2025 Set 2NAT2 marksMedium (estimate)
GATE CS 2025 Set 2, Q.57
In a $B^{+}$ -tree where each node can hold at most four key values, a root to leaf path consists of the following nodes…
File Organization, B-Trees and B+ Trees Indexing
GATE CS 2024 Set 1MCQ1 markEasy (estimate)
GATE CS 2024 Set 1, Q.20
Let S be the specification: "Instructors teach courses. Students register for courses. Courses are allocated classrooms. Instructors guide students." Which one of the following...
ER Model and Relational Schema Design
GATE CS 2024 Set 1MCQ1 markEasy (estimate)
GATE CS 2024 Set 1, Q.21
In a B+ tree, the requirement of at least half-full (50%) node occupancy is relaxed for which one of the following cases?
File Organization, B-Trees and B+ Trees Indexing
GATE CS 2024 Set 1MSQ1 markEasy (estimate)
GATE CS 2024 Set 1, Q.22
Which of the following statements about a relation R in first normal form (1NF) is/are TRUE ?
Functional Dependencies and Normalization
GATE CS 2024 Set 1NAT1 markEasy (estimate)
GATE CS 2024 Set 1, Q.35
Consider the following two relations, $R (A, B)$ and $S (A, C)$ : R.A R.B 10 20 20 30 30 40 30 50 50 95 S.A S.C 10 90 30 45 40 80 The total number of tuples obtained by evaluating th...
Relational Algebra and Tuple Relational Calculus
GATE CS 2024 Set 1MSQ2 marksEasy (estimate)
GATE CS 2024 Set 1, Q.44
The symbol $\to$ indicates functional dependency in the context of a relational database. Which of the following options is/are TRUE?
Functional Dependencies and Normalization
GATE CS 2024 Set 1MSQ2 marksEasy (estimate)
GATE CS 2024 Set 1, Q.46
Consider the following read-write schedule $S$ over three transactions $T_{1}, T_{2}$ , and $T_{3}$ , where the subscripts in the schedule indicate transaction IDs…
Transactions, Serializability and Concurrency Control
GATE CS 2024 Set 2MCQ1 markEasy (estimate)
GATE CS 2024 Set 2, Q.19
Once the DBMS informs the user that a transaction has been successfully completed, its effect should persist even if the system crashes before all its changes are reflected on d...
Transactions, Serializability and Concurrency Control
GATE CS 2024 Set 2MCQ1 markEasy (estimate)
GATE CS 2024 Set 2, Q.20
In the context of owner and weak entity sets in the ER (Entity-Relationship) data model, which one of the following statements is TRUE?
ER Model and Relational Schema Design
GATE CS 2024 Set 2MSQ1 markEasy (estimate)
GATE CS 2024 Set 2, Q.26
Which of the following file organizations is/are I/O efficient for the scan operation in DBMS?
File Organization, B-Trees and B+ Trees Indexing
GATE CS 2024 Set 2MSQ1 markEasy (estimate)
GATE CS 2024 Set 2, Q.27
Which of the following statements about the Two Phase Locking (2PL) protocol is/are TRUE?
Transactions, Serializability and Concurrency Control
GATE CS 2024 Set 2MCQ2 marksMedium (estimate)
GATE CS 2024 Set 2, Q.45
The relation schema, Person(pid,city), describes the city of residence for every person uniquely identified by pid. The following relational algebra operators are available:...
Relational Algebra and Tuple Relational Calculus
GATE CS 2024 Set 2NAT2 marksMedium (estimate)
GATE CS 2024 Set 2, Q.56
A functional dependency $F : X \to Y$ is termed as a useful functional dependency if and only if it satisfies all the following three conditions: - $X$ is not the empty s...
Functional Dependencies and Normalization · Combinatorics, Counting, Recurrence Relations and Generating Functions
GATE CS 2023MCQ1 markEasy (estimate)
GATE CS 2023, Q.16
Which one of the options given below refers to the degree (or arity) of a relation in relational database systems?
ER Model and Relational Schema Design
GATE CS 2023NAT2 marksEasy (estimate)
GATE CS 2023, Q.61
Consider the following table named Student in a relational database. The primary key of this table is rollNum. rollNum name gender marks 1 Naman M 62 2 Aliya F 70 3 Aliya F 80 4...
SQL Queries and Integrity Constraints
GATE CS 2023NAT2 marksMedium (estimate)
GATE CS 2023, Q.62
Consider a database of fixed-length records, stored as an ordered file. The database has 25,000 records, with each record being 100 bytes, of which the primary key occupies 15 b...
File Organization, B-Trees and B+ Trees Indexing
GATE CS 2022MCQ1 markEasy (estimate)
GATE CS 2022, Q.14
In a relational data model, which one of the following statements is TRUE?
Functional Dependencies and Normalization
GATE CS 2022MSQ1 markMedium (estimate)
GATE CS 2022, Q.25
Consider the following three relations in a relational database.…
Relational Algebra and Tuple Relational Calculus
GATE CS 2022NAT1 markEasy (estimate)
GATE CS 2022, Q.31
Consider a relation $R (A, B, C, D, E)$ with the following three functional dependencies. $A B \to C; B C \to D; C \to E;$ The number of superkeys in the relation R i...
Functional Dependencies and Normalization
GATE CS 2022MCQ2 marksMedium (estimate)
GATE CS 2022, Q.39
Let $R_{i} (z)$ and $W_{i} (z)$ denote read and write operations on a data element $z$ by a transaction $T_{i}$ , respectively. Consider the schedule $S$ with four transactions.…
Transactions, Serializability and Concurrency Control
GATE CS 2022NAT2 marksMedium (estimate)
GATE CS 2022, Q.56
Consider the relational database with the following four schemas and their respective instances. Student(sNo, sName, dNo), Dept(dNo, dName), Course(cNo, cName, dNo), Register(sN...
SQL Queries and Integrity Constraints
GATE CS 2021 Set 1MSQ1 markMedium (estimate)
GATE CS 2021 Set 1, Q.23 (CS Q.13)
Suppose a database system crashes again while recovering from a previous crash. Assume checkpointing is not done by the database either during the transactions or during recover...
Transactions, Serializability and Concurrency Control
GATE CS 2021 Set 1NAT1 markMedium (estimate)
GATE CS 2021 Set 1, Q.33 (CS Q.23)
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...
Relational Algebra and Tuple Relational Calculus
GATE CS 2021 Set 1MCQ2 marksMedium (estimate)
GATE CS 2021 Set 1, Q.37 (CS Q.27)
The following relation records the age of 500 employees of a company, where empNo (indicating the employee number) is the key: $empAge (empNo, age)$ Consid...
Relational Algebra and Tuple Relational Calculus
GATE CS 2021 Set 1MCQ2 marksEasy (estimate)
GATE CS 2021 Set 1, Q.42 (CS Q.32)
Let $r_{i} (z)$ and $w_{i} (z)$ denote read and write operations respectively on a data item $z$ by a transaction $T_{i}$ . Consider the following two schedules.…
Transactions, Serializability and Concurrency Control
GATE CS 2021 Set 1MCQ2 marksMedium (estimate)
GATE CS 2021 Set 1, Q.43 (CS Q.33)
Consider the relation $R (P, Q, S, T, X, Y, Z, W)$ with the following functional dependencies.…
Functional Dependencies and Normalization
GATE CS 2021 Set 1MSQ2 marksHard (estimate)
GATE CS 2021 Set 1, Q.57 (CS Q.47)
Consider a dynamic hashing approach for 4-bit integer keys: 1. There is a main hash table of size 4. 2. The 2 least significant bits of a key is used to index into the main hash...
File Organization, B-Trees and B+ Trees Indexing
GATE CS 2021 Set 2MCQ1 markEasy (estimate)
GATE CS 2021 Set 2, Q.16 (CS Q.6)
Consider the following statements $S_{1}$ and $S_{2}$ about the relational data model: $S_{1}$ : A relation scheme can have at most one foreign key. $S_{2}$ : A foreign key in a relation...
ER Model and Relational Schema Design
GATE CS 2021 Set 2NAT1 markMedium (estimate)
GATE CS 2021 Set 2, Q.31 (CS Q.21)
A data file consisting of 1,50,000 student-records is stored on a hard disk with block size of 4096 bytes. The data file is sorted on the primary key RollNo. The size of a rec...
File Organization, B-Trees and B+ Trees Indexing
GATE CS 2021 Set 2MCQ2 marksEasy (estimate)
GATE CS 2021 Set 2, Q.41 (CS Q.31)
The relation scheme given below is used to store information about the employees of a company, where empId is the key and deptId indicates the department to which the employ...
SQL Queries and Integrity Constraints
GATE CS 2021 Set 2MCQ2 marksMedium (estimate)
GATE CS 2021 Set 2, Q.42 (CS Q.32)
Let $S$ be the following schedule of operations of three transactions $T_{1}$ , $T_{2}$ and $T_{3}$ in a relational database system…
Transactions, Serializability and Concurrency Control
GATE CS 2021 Set 2MSQ2 marksEasy (estimate)
GATE CS 2021 Set 2, Q.50 (CS Q.40)
Suppose the following functional dependencies hold on a relation $U$ with attributes $P, Q, R, S$ , and $T$ : $P \to QR$ $R S \to T$ Which of the following functional dependenc...
Functional Dependencies and Normalization
GATE CS 2020MCQ1 markMedium (estimate)
GATE CS 2020, Q.23 (CS Q.13)
Consider a relational database containing the following schemas. sno pno cost S1 P1 150 S1 P2 50 S1 P3 100 S2 P4 200 S2 P5 250 S3 P1 250 S3 P2 150 S3 P5 300 S3 P4 250 sno sname...
SQL Queries and Integrity Constraints
GATE CS 2020MCQ1 markEasy (estimate)
GATE CS 2020, Q.24 (CS Q.14)
Which one of the following is used to represent the supporting many-one relationships of a weak entity set in an entity-relationship diagram?
ER Model and Relational Schema Design
GATE CS 2020MCQ2 marksEasy (estimate)
GATE CS 2020, Q.46 (CS Q.36)
Consider a relational table $R$ that is in 3NF, but not in BCNF. Which one of the following statements is TRUE?
Functional Dependencies and Normalization
GATE CS 2020MCQ2 marksMedium (estimate)
GATE CS 2020, Q.47 (CS Q.37)
Consider a schedule of transactions $T_{1}$ and $T_{2}$ given below.…
Transactions, Serializability and Concurrency Control
GATE CS 2020NAT2 marksMedium (estimate)
GATE CS 2020, Q.64 (CS Q.54)
Consider a database implemented using B+ tree for file indexing and installed on a disk drive with block size of 4 KB. The size of search key is 12 bytes and the size of tree/di...
File Organization, B-Trees and B+ Trees Indexing
GATE CS 2019MCQ1 markMedium (estimate)
GATE CS 2019, Q.21 (CS Q.11)
Consider the following two statements about database transaction schedules: I. Strict two-phase locking protocol generates conflict serializable schedules that are also recovera...
Transactions, Serializability and Concurrency Control
GATE CS 2019MCQ1 markEasy (estimate)
GATE CS 2019, Q.24 (CS Q.14)
Which one of the following statements is NOT correct about the B+ tree data structure used for creating an index of a relational database table?
File Organization, B-Trees and B+ Trees Indexing
GATE CS 2019MCQ2 marksMedium (estimate)
GATE CS 2019, Q.42 (CS Q.32)
Let the set of functional dependencies $F = {QR \to S, R \to P, S \to Q}$ hold on a relation schema $X = (P QR S)$ . $X$ is not in BCNF. Suppose $X$ is decomposed into two schema...
Functional Dependencies and Normalization
GATE CS 2019NAT2 marksMedium (estimate)
GATE CS 2019, Q.61 (CS Q.51)
A relational database contains two tables Student and Performance as shown below: Student | Roll_no. | Student_name | | :--- | :--- | | 1 | Amit | | 2 | Priya | | 3 | Vi...
SQL Queries and Integrity Constraints
GATE CS 2019NAT2 marksMedium (estimate)
GATE CS 2019, Q.65 (CS Q.55)
Consider the following relations $P (X, Y, Z)$ , $Q (X, Y, T)$ and $R (Y, V)$ : P | X | Y | Z | | :--- | :--- | :--- | | X1 | Y1 | Z1 | | X1 | Y1 | Z2 | | X2 | Y2 | Z2 | | X2 | Y...
Relational Algebra and Tuple Relational Calculus
GATE CS 2018MCQ1 markEasy (estimate)
GATE CS 2018, Q.21 (CS Q.11)
In an Entity-Relationship (ER) model, suppose $R$ is a many-to-one relationship from entity set E1 to entity set E2. Assume that E1 and E2 participate totally in $R$ and that th...
ER Model and Relational Schema Design
GATE CS 2018MCQ1 markEasy (estimate)
GATE CS 2018, Q.22 (CS Q.12)
Consider the following two tables and four queries in SQL. Book (isbn, bname), Stock (isbn, copies) Query 1: SELECT B.isbn, S.copies FROM Book B INNER JOIN Stock S ON B.isbn = S...
Relational Algebra and Tuple Relational Calculus
GATE CS 2018MCQ2 marksMedium (estimate)
GATE CS 2018, Q.51 (CS Q.41)
Consider the relations $r (A, B)$ and $s (B, C)$ , where $s . B$ is a primary key and $r . B$ is a foreign key referencing $s . B$ . Consider the query $Q : r ⋈ (σ_{B < 5} (s))$ ...
Relational Algebra and Tuple Relational Calculus
GATE CS 2018MCQ2 marksMedium (estimate)
GATE CS 2018, Q.52 (CS Q.42)
Consider the following four relational schemas. For each schema, all non-trivial functional dependencies are listed. The underlined attributes are the respective primary keys. S...
Functional Dependencies and Normalization
GATE CS 2017 Set 1MCQ1 markMedium (estimate)
GATE CS 2017 Set 1, Q.16 (CS Q.16)
The following functional dependencies hold true for the relational schema $R (V, W, X, Y, Z)$ : $V \to W$ $V W \to X$ $Y \to V X$ $Y \to Z$ Which of the following is irreduc...
Functional Dependencies and Normalization
GATE CS 2017 Set 1NAT1 markMedium (estimate)
GATE CS 2017 Set 1, Q.23 (CS Q.23)
Consider a database that has the relation schema $EMP (EmpId, EmpName, DeptName)$ . An instance of the schema EMP and a SQL query on it are given below...
SQL Queries and Integrity Constraints
GATE CS 2017 Set 1MCQ2 marksHard (estimate)
GATE CS 2017 Set 1, Q.41 (CS Q.41)
Consider a database that has the relation schemas EMP(EmpId, EmpName, DeptId), and DEPT(DeptName, DeptId). Note that the DeptId can be permitted to be NULL in the relation EMP....
Relational Algebra and Tuple Relational Calculus
GATE CS 2017 Set 1MCQ2 marksMedium (estimate)
GATE CS 2017 Set 1, Q.42 (CS Q.42)
In a database system, unique timestamps are assigned to each transaction using Lamport's logical clock. Let $TS (T_{1})$ and $TS (T_{2})$ be the timestamps of transactio...
Transactions, Serializability and Concurrency Control
GATE CS 2017 Set 1NAT2 marksMedium (estimate)
GATE CS 2017 Set 1, Q.46 (CS Q.46)
Consider a database that has the relation schema $CR (StudentName, CourseName)$ . An instance of the schema CR is as given below. StudentName CourseName SA CA...
Relational Algebra and Tuple Relational Calculus
GATE CS 2017 Set 2MCQ1 markMedium (estimate)
GATE CS 2017 Set 2, Q.17 (CS Q.17)
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 condi...
ER Model and Relational Schema Design
GATE CS 2017 Set 2NAT1 markMedium (estimate)
GATE CS 2017 Set 2, Q.19 (CS Q.19)
Consider the following tables T1 and T2. Table T1 | P | Q | | :-: | :-: | | 2 | 2 | | 3 | 8 | | 7 | 3 | | 5 | 8 | | 6 | 9 | | 8 | 5 | | 9 | 8 | Table T2 | R | S | | :-:...
ER Model and Relational Schema Design · SQL Queries and Integrity Constraints
GATE CS 2017 Set 2NAT2 marksHard (estimate)
GATE CS 2017 Set 2, Q.44 (CS Q.44)
Two transactions $T_{1}$ and $T_{2}$ are given as $T_{1} T_{2} : r_{1} (X) w_{1} (X) r_{1} (Y) w_{1} (Y) : r_{2} (Y) w_{2} (Y) r_{2} (Z) w_{2} (Z)$ where $r_{i} (V)$ denotes a...
Transactions, Serializability and Concurrency Control
GATE CS 2017 Set 2NAT2 marksMedium (estimate)
GATE CS 2017 Set 2, Q.46 (CS Q.46)
Consider the following database table named top_scorer. | player | country | goals | | :--- | :--- | :---: | | Klose | Germany | 16 | | Ronaldo | Brazil | 15 | | G Müller | Ge...
SQL Queries and Integrity Constraints
GATE CS 2017 Set 2NAT2 marksMedium (estimate)
GATE CS 2017 Set 2, Q.49 (CS Q.49)
In a B+ tree, if the search-key value is 8 bytes long, the block size is 512 bytes and the block pointer size is 2 bytes, then the maximum order of the B+ tree is
File Organization, B-Trees and B+ Trees Indexing
GATE CS 2016 Set 1MCQ1 markEasy (estimate)
GATE CS 2016 Set 1, Q.31 (CS Q.21)
Which of the following is NOT a superkey in a relational schema with attributes $V, W, X, Y, Z$ and primary key $V Y$ ?
ER Model and Relational Schema Design
GATE CS 2016 Set 1MCQ1 markEasy (estimate)
GATE CS 2016 Set 1, Q.32 (CS Q.22)
Which one of the following is NOT a part of the ACID properties of database transactions?
Transactions, Serializability and Concurrency Control
GATE CS 2016 Set 1MCQ1 markMedium (estimate)
GATE CS 2016 Set 1, Q.33 (CS Q.23)
A database of research articles in a journal uses the following schema.…
Functional Dependencies and Normalization
GATE CS 2016 Set 1MCQ2 marksEasy (estimate)
GATE CS 2016 Set 1, Q.61 (CS Q.51)
Consider the following two phase locking protocol. Suppose a transaction $T$ accesses (for read or write operations), a certain set of objects ${O_{1}, \dots, O_{k}}$ . This is don...
Transactions, Serializability and Concurrency Control
GATE CS 2016 Set 2MCQ1 markEasy (estimate)
GATE CS 2016 Set 2, Q.31 (CS Q.21)
B+ Trees are considered BALANCED because
File Organization, B-Trees and B+ Trees Indexing
GATE CS 2016 Set 2MCQ1 markEasy (estimate)
GATE CS 2016 Set 2, Q.32 (CS Q.22)
Suppose a database schedule $S$ involves transactions $T_{1}, \dots, T_{n}$ . Construct the precedence graph of $S$ with vertices representing the transactions and edges representing...
Transactions, Serializability and Concurrency Control
GATE CS 2016 Set 2MCQ2 marksMedium (estimate)
GATE CS 2016 Set 2, Q.61 (CS Q.51)
Consider the following database schedule with two transactions, $T_{1}$ and $T_{2}$ . $S = r_{2} (X); r_{1} (X); r_{2} (Y); w_{1} (X); r_{1} (Y); w_{2} (X); a_{1}; a_{2}$ where $r_{i} (Z)$ denotes a read o...
Transactions, Serializability and Concurrency Control
GATE CS 2016 Set 2NAT2 marksEasy (estimate)
GATE CS 2016 Set 2, Q.62 (CS Q.52)
Consider the following database table named water_schemes: scheme_no | district_name | capacity 1 | Ajmer | 20 1 | Bikaner | 10 2 | Bikaner | 10 3 | Bikaner | 20 1 | Churu | 1...
SQL Queries and Integrity Constraints
GATE CS 2015 Set 1MCQ1 markEasy (estimate)
GATE CS 2015 Set 1, Q.17 (CS Q.7)
SELECT operation in SQL is equivalent to:
SQL Queries and Integrity Constraints
GATE CS 2015 Set 1MCQ1 markEasy (estimate)
GATE CS 2015 Set 1, Q.34 (CS Q.24)
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:
File Organization, B-Trees and B+ Trees Indexing
GATE CS 2015 Set 1NAT2 marksEasy (estimate)
GATE CS 2015 Set 1, Q.37 (CS Q.27)
Consider the following relations: Student | Roll No | Student Name | | :---: | :---: | | 1 | Raj | | 2 | Rohit | | 3 | Raj | Performance | Roll No | Course | Marks | | :...
SQL Queries and Integrity Constraints
GATE CS 2015 Set 1NAT2 marksMedium (estimate)
GATE CS 2015 Set 1, Q.51 (CS Q.41)
Consider an Entity-Relationship (ER) model in which entity sets $E_{1}$ and $E_{2}$ are connected by an $m : n$ relationship $R_{12}$ . $E_{1}$ and $E_{3}$ are connected by a $1 : n$ ( $1$ on...
ER Model and Relational Schema Design
GATE CS 2015 Set 2MCQ1 markEasy (estimate)
GATE CS 2015 Set 2, Q.11 (CS Q.1)
Consider the following transaction involving two bank accounts $x$ and $y$ .…
Transactions, Serializability and Concurrency Control
GATE CS 2015 Set 2NAT1 markMedium (estimate)
GATE CS 2015 Set 2, Q.16 (CS Q.6)
With reference to the B+ tree index of order 1 shown below, the minimum number of nodes (including the Root node) that must be fetched in order to satisfy the following query: "...
File Organization, B-Trees and B+ Trees Indexing
GATE CS 2015 Set 2MCQ2 marksEasy (estimate)
GATE CS 2015 Set 2, Q.42 (CS Q.32)
Consider two relations $R_{1} (A, B)$ with the tuples $(1, 5), (3, 7)$ and $R_{2} (A, C)$ with $(1, 7), (4, 9)$ . Assume that $R (A, B, C)$ is the full natural outer join of $R_{1}$ and…
Relational Algebra and Tuple Relational Calculus
GATE CS 2015 Set 2MCQ2 marksMedium (estimate)
GATE CS 2015 Set 2, Q.56 (CS Q.46)
Consider a simple checkpointing protocol and the following set of operations in the log: (start, T4); (write, T4, y, 2, 3); (start, T1); (commit, T4); (write, T1, z, 5, 7);…
Transactions, Serializability and Concurrency Control
GATE CS 2015 Set 3MCQ1 markEasy (estimate)
GATE CS 2015 Set 3, Q.13 (CS Q.3)
Consider the following relation $Cinema (theater, address, capacity)$ Which of the following options will be needed at the end of the SQL query ...
SQL Queries and Integrity Constraints · Relational Algebra and Tuple Relational Calculus
GATE CS 2015 Set 3MCQ1 markEasy (estimate)
GATE CS 2015 Set 3, Q.30 (CS Q.20)
Consider the relation $X (P, Q, R, S, T, U)$ with the following set of functional dependencies $F = {{P, R} \to {S, T}, {P, S, U} \to {Q, R}}$ Which of the followi...
Functional Dependencies and Normalization
GATE CS 2015 Set 3MCQ2 marksMedium (estimate)
GATE CS 2015 Set 3, Q.39 (CS Q.29)
Consider the following partial Schedule $S$ involving two transactions $T 1$ and $T 2$ . Only the read and the write operations have been shown. The read operation on data item $P$ ...
Transactions, Serializability and Concurrency Control
GATE CS 2015 Set 3NAT2 marksMedium (estimate)
GATE CS 2015 Set 3, Q.56 (CS Q.46)
Consider a B+ tree in which the search key is 12 bytes long, block size is 1024 bytes, record pointer is 10 bytes long and block pointer is 8 bytes long. The maximum number of k...
File Organization, B-Trees and B+ Trees Indexing
GATE CS 2014 Set 1MCQ1 markEasy (estimate)
GATE CS 2014 Set 1, Q.31 (CS Q.21)
Consider the relation scheme $R = (E, F, G, H, I, J, K, L, M, N)$ and the set of functional dependencies…
Functional Dependencies and Normalization
GATE CS 2014 Set 1MCQ1 markMedium (estimate)
GATE CS 2014 Set 1, Q.32 (CS Q.22)
Given the following statements: S1: A foreign key declaration can always be replaced by an equivalent check assertion in SQL. S2: Given the table R(a,b,c) where a and b together...
SQL Queries and Integrity Constraints
GATE CS 2014 Set 1MCQ2 marksMedium (estimate)
GATE CS 2014 Set 1, Q.39 (CS Q.29)
Consider the following four schedules due to three transactions (indicated by the subscript) using read and write on a data item x, denoted by r(x) and w(x) respectively. Which...
Transactions, Serializability and Concurrency Control
GATE CS 2014 Set 1MCQ2 marksMedium (estimate)
GATE CS 2014 Set 1, Q.40 (CS Q.30)
Given the following two statements: S1: Every table with two single-valued attributes is in 1NF, 2NF, 3NF and BCNF. S2: AB $\to$ C, D $\to$ E, E $\to$ C is a minimal cover for the set...
Functional Dependencies and Normalization
GATE CS 2014 Set 1MCQ2 marksMedium (estimate)
GATE CS 2014 Set 1, Q.64 (CS Q.54)
Given the following schema: employees(emp-id, first-name, last-name, hire-date, dept-id, salary) departments(dept-id, dept-name, manager-id, location-id) You want to...
SQL Queries and Integrity Constraints
GATE CS 2014 Set 2NAT1 markEasy (estimate)
GATE CS 2014 Set 2, Q.31 (CS Q.21)
The maximum number of superkeys for the relation schema $R (E, F, G, H)$ with $E$ as the key is _____.
Functional Dependencies and Normalization
GATE CS 2014 Set 2NAT1 markEasy (estimate)
GATE CS 2014 Set 2, Q.32 (CS Q.22)
Given an instance of the STUDENTS relation as shown below: | StudentID | StudentName | StudentEmail | StudentAge | CPI | | :--- | :--- | :--- | :--- | :--- | | 2345 | Shankar |...
ER Model and Relational Schema Design
GATE CS 2014 Set 2MCQ2 marksMedium (estimate)
GATE CS 2014 Set 2, Q.39 (CS Q.29)
Consider the following schedule S of transactions T1, T2, T3, T4: | T1 | T2 | T3 | T4 | | :--- | :--- | :--- | :--- | | | Reads(X) | | | | | | Writes(X) / Commit | | | Write...
Transactions, Serializability and Concurrency Control
GATE CS 2014 Set 2MCQ2 marksEasy (estimate)
GATE CS 2014 Set 2, Q.40 (CS Q.30)
Consider a join (relational algebra) between relations $r (R)$ and $s (S)$ using the nested loop method. There are 3 buffers each of size equal to disk block size, out of which on...
File Organization, B-Trees and B+ Trees Indexing
GATE CS 2014 Set 2MCQ2 marksMedium (estimate)
GATE CS 2014 Set 2, Q.64 (CS Q.54)
SQL allows duplicate tuples in relations, and correspondingly defines the multiplicity of tuples in the result of joins. Which one of the following queries always gives the same...
SQL Queries and Integrity Constraints
GATE CS 2014 Set 3MCQ1 markEasy (estimate)
GATE CS 2014 Set 3, Q.31 (CS Q.21)
What is the optimized version of the relation algebra expression $π_{A 1} (π_{A 2} (σ_{F 1} (σ_{F 2} (r))))$ , where $A 1, A 2$ are sets of attributes in $r$ with…
Relational Algebra and Tuple Relational Calculus
GATE CS 2014 Set 3MCQ1 markEasy (estimate)
GATE CS 2014 Set 3, Q.32 (CS Q.22)
A prime attribute of a relation scheme $R$ is an attribute that appears
Functional Dependencies and Normalization
GATE CS 2014 Set 3MCQ2 marksMedium (estimate)
GATE CS 2014 Set 3, Q.39 (CS Q.29)
Consider the transactions T1, T2, and T3 and the schedules S1 and S2 given below. T1: r1(X); r1(Z); w1(X); w1(Z) T2: r2(Y); r2(Z); w2(Z) T3: r3(Y); r3(X); w3(Y) S1: r1(X); r3(Y)...
Transactions, Serializability and Concurrency Control
GATE CS 2014 Set 3MCQ2 marksMedium (estimate)
GATE CS 2014 Set 3, Q.40 (CS Q.30)
Consider the relational schema given below, where eId of the relation dependent is a foreign key referring to empId of the relation employee. Assume that every employee has at l...
Relational Algebra and Tuple Relational Calculus
GATE CS 2014 Set 3MCQ2 marksEasy (estimate)
GATE CS 2014 Set 3, Q.64 (CS Q.54)
Consider the following relational schema: employee(empId, empName, empDept) customer(custId, custName, salesRepId, rating) salesRepId is a foreign key referring to e...
SQL Queries and Integrity Constraints
GATE CS 2013MCQ1 markEasy (estimate)
GATE CS 2013, Q.15 (CS Q.15)
An index is clustered, if
File Organization, B-Trees and B+ Trees Indexing
GATE CS 2013MCQ2 marksMedium (estimate)
GATE CS 2013, Q.35 (CS Q.35)
Consider the following relational schema. $Students (rollno : integer, sname : string)$ …
Relational Algebra and Tuple Relational Calculus
GATE CS 2013MCQ2 marksMedium (estimate)
GATE CS 2013, Q.54 (CS Q.54)
How many candidate keys does the relation R have?
Functional Dependencies and Normalization
GATE CS 2013MCQ2 marksMedium (estimate)
GATE CS 2013, Q.55 (CS Q.55)
The relation R is
Functional Dependencies and Normalization
GATE CS 2012MCQ1 markEasy (estimate)
GATE CS 2012, Q.2 (CS Q.2)
Which of the following is TRUE?
Functional Dependencies and Normalization
GATE CS 2012MCQ1 markEasy (estimate)
GATE CS 2012, Q.14 (CS Q.14)
Given the basic ER and relational models, which of the following is INCORRECT?
Relational Algebra and Tuple Relational Calculus · ER Model and Relational Schema Design
GATE CS 2012MCQ1 markMedium (estimate)
GATE CS 2012, Q.15 (CS Q.15)
Which of the following statements are TRUE about an SQL query? $P$ : An SQL query can contain a HAVING clause even if it does not have a GROUP BY clause $Q$ : An SQL query can con...
SQL Queries and Integrity Constraints
GATE CS 2012MCQ2 marksMedium (estimate)
GATE CS 2012, Q.27 (CS Q.27)
Consider the following transactions with data items $P$ and $Q$ initialized to zero: $T_{1}$ : read ( $P$ ); read ( $Q$ ); if $P = 0$ then $Q := Q + 1$ ; write ( $Q$ ). $T_{2}$ : read ( $Q$ );...
Transactions, Serializability and Concurrency Control
GATE CS 2012MCQ2 marksEasy (estimate)
GATE CS 2012, Q.43 (CS Q.43)
Suppose $R_{1} (A, B)$ and $R_{2} (C, D)$ are two relation schemas. Let $r_{1}$ and $r_{2}$ be the corresponding relation instances. $B$ is a foreign key that refers to $C$ in $R_{2}$ . If d...
Relational Algebra and Tuple Relational Calculus · Relational Algebra and Tuple Relational Calculus
GATE CS 2012MCQ2 marksMedium (estimate)
GATE CS 2012, Q.50 (CS Q.50)
How many tuples does the result of the following relational algebra expression contain? Assume that the schema of $A \cup B$ is the same as that of $A$ .…
Relational Algebra and Tuple Relational Calculus
GATE CS 2012MCQ2 marksMedium (estimate)
GATE CS 2012, Q.51 (CS Q.51)
How many tuples does the result of the following SQL query contain? SELECT A.Id FROM A WHERE A.Age > ALL (SELECT B.Age FROM B WHERE B.Name = 'Arun')
SQL Queries and Integrity Constraints
GATE CS 2011MCQ1 markEasy (estimate)
GATE CS 2011, Q.12 (CS Q.12)
Consider a relational table with a single record for each registered student with the following attributes. 1. Registration_Num: Unique registration number of each registered st...
ER Model and Relational Schema Design
GATE CS 2011MCQ2 marksMedium (estimate)
GATE CS 2011, Q.32 (CS Q.32)
Consider a database table $T$ containing two columns $X$ and $Y$ each of type integer. After the creation of the table, one record $(X = 1, Y = 1)$ is inserted in the table. Let…
SQL Queries and Integrity Constraints
GATE CS 2011MCQ2 marksEasy (estimate)
GATE CS 2011, Q.39 (CS Q.39)
Consider a relational table $r$ with sufficient number of records, having attributes $A_{1}, A_{2}, \dots, A_{n}$ and let $1 \leq p \leq n$ . Two queries Q1 and Q2 are given below. Q1…
File Organization, B-Trees and B+ Trees Indexing
GATE CS 2011MCQ2 marksEasy (estimate)
GATE CS 2011, Q.46 (CS Q.46)
Database table by name Loan_Records is given below. Borrower Bank_Manager Loan_Amount Ramesh Sunderajan 10000.00 Suresh Ramgopal 5000.00 Mahesh Sunderajan 7000.00 What is the...
SQL Queries and Integrity Constraints