Probability Engine · MDS 505

Database Management Systems: the questions likely to come

113 analyzed questions from 13 past papers (4 board exams, 2078-2082), grouped by syllabus unit — each with its probability, how often it's been asked, and where to study the answer.

13
Papers analyzed
incl. 4 board exams · 2078-2082
113
Analyzed questions
across 7 syllabus units
20%
Board marks from repeats
questions asked before
5
Units = 80% of marks
study these first
Model answers for this subject are being written. Every question links to its original paper so you can study from the source meanwhile.
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U6 · Q1/8 · 20796 marks
Trends in Database Technology

Explain different types of RAID.

OR

Differentiate between classification and clustering. Explain any one clustering algorithm.

28%
Occasional to appearAppeared in 1 of the last 1 board papers
Seen in
How well do you know this?rating moves you on
MODEL ANSWERU6 · 6 marks

Types of RAID (Redundant Array of Independent Disks)

RAID combines multiple physical disks into one logical unit to improve performance (via striping/parallelism) and reliability (via mirroring/parity). The standard levels are:

LevelTechniqueMin disksRedundancyNotes
RAID 0Striping, no redundancy2NoneData split across disks → high speed, but one failure loses everything
RAID 1Mirroring2Full copyEvery block written to two disks; survives one disk failure; 50% storage overhead
RAID 2Bit-level striping with Hamming-code ECC—ECCObsolete; complex, not used in practice
RAID 3Byte-level striping + dedicated parity disk3Single parityGood for large sequential I/O; parity disk is a bottleneck
RAID 4Block-level striping + dedicated parity disk3Single parityParity disk becomes a write bottleneck
RAID 5Block-level striping + distributed parity3Single parityParity spread across all disks → no bottleneck; survives one failure; popular
RAID 6Block striping + two independent parities (P+Q)4Dual paritySurvives two simultaneous disk failures
RAID 10 (1+0)Mirror + stripe4MirroringHigh performance and high reliability; combines RAID 1 and RAID 0

Parity illustration (RAID 5): for stripes A0,A1,A2A_0, A_1, A_2 the parity is P=A0⊕A1⊕A2P = A_0 \oplus A_1 \oplus A_2. If one disk fails, its data is recovered by XOR-ing the surviving blocks with the parity.

Disk1   Disk2   Disk3   Disk4
 A0      A1      A2      Ap     <- parity distributed
 B0      B1      Bp      B2
 C0      Cp      C1      C2

Summary: RAID 0 = pure speed (no safety); RAID 1 = pure safety (mirroring); RAID 5 = balanced speed + single-failure protection with low overhead; RAID 6 = double-failure protection; RAID 10 = best of speed and reliability at higher cost.

AI-generated answerView in 2079 paper →
U6 · Question 1 of 8
Question Priority · U6ranked by appearance likelihood — study top-down

Trends in Database Technology

Analyzed next36%
1
★ TOP PICK

Explain different types of RAID.

OR

Differentiate between classification and clustering. Explain any one clustering algorithm.

6 marksSEEN IN
28%
2

Define parallel database with its possible architectures.

6 marksSEEN IN
36%
3

Create B tree of order(M) = 3 for the following values: 1, 4, 11, 3, 7, 12, 2, 5, 15, 13, 6

OR

Explain different data warehouse schemas.

6 marksSEEN IN
25%
4

Write short notes on a) Mobile Database b) DML

6 marksSEEN IN
25%
5

How database records are mapped to files using fixed length record and variable length record approaches? Justify with examples. [6]

6 marksSEEN IN
23%
6

How fixed length attributes and variable length attributes are represented in variable length record approach in file organization? What is a slotted page structure? (4 + 2)

6 marksSEEN IN
21%
7

Explain B-tree Index files.

6 marksSEEN IN
19%
8

Briefly explain spatial database.

3 marksSEEN IN
19%
03The mock

Sit a probable paper

A full mock exam built from the most likely questions, mirroring the real paper's structure. Every slot is a real past question.

Most Probable Paper

Mirrors the real structure · 45 marks · based on 5 past papers

Group A
  1. 1.

    What is three schema architecture?

    [3 marks]
    Fundamental Concept of DBMSVery likelyfrom 2081 paper →

    This question has recurred in 2 of 5 years; including the board exam 1× (2081); and its topic (Fundamental Concept of DBMS) appears in 100% of years.

  2. 2.

    Highlight on the desirable properties of transactions.

    [3 marks]
    Transaction Processing and Concurrency ControlVery likelyfrom 2079 paper →

    This question has recurred in 2 of 5 years; including the board exam 1× (2079); and its topic (Transaction Processing and Concurrency Control) appears in 100% of years.

  3. 3.

    Explain weak entity set.

    [3 marks]
    Fundamental Concept of DBMSVery likelyfrom 2082 paper →

    This question has recurred in 3 of 5 years; so far only in internal assessments, not the board; and its topic (Fundamental Concept of DBMS) appears in 100% of years.

  4. 4.

    List different types of data models and explain anyone.

    [3 marks]
    Fundamental Concept of DBMSVery likelyfrom 2082 paper →

    Asked once (2082); including the board exam 1× (2082); and its topic (Fundamental Concept of DBMS) appears in 100% of years.

  5. 5.

    Explain the concept of data abstraction in DBMS.

    [3 marks]
    Fundamental Concept of DBMSVery likelyfrom 2082 paper →

    Asked once (2082); including the board exam 1× (2082); and its topic (Fundamental Concept of DBMS) appears in 100% of years.

Group B
  1. 1.

    What do you understand by query optimization? Explain.

    [6 marks]
    SQL & Query OptimizationLikelyfrom 2082 paper →

    This question has recurred in 3 of 5 years; including the board exam 3× (2080 to 2082); and its topic recurs in 3 of 5 years.

  2. 2.

    Explain different types of RAID.

    OR

    Differentiate between classification and clustering. Explain any one clustering algorithm.

    [6 marks]
    Trends in Database TechnologyVery likelyfrom 2079 paper →

    This question has recurred in 2 of 5 years; including the board exam 1× (2079); and its topic (Trends in Database Technology) appears in 100% of years.

  3. 3.

    Describe different architectures in parallel databases. [6]

    OR

    How fixed length attributes and variable length attributes are represented in variable length record approach in file organization? What is a slotted page structure? [4+2]

    [6 marks]
    Trends in Database TechnologyVery likelyfrom 2080 paper →

    This question has recurred in 2 of 5 years; including the board exam 1× (2080); and its topic (Trends in Database Technology) appears in 100% of years.

  4. 4.

    Explain the concept of recoverable, cascade less, and strict schedule.

    OR

    Which of the following schedule is (conflict) serializable? For each serializable schedule, determine the equivalent serial schedules.

    i) r1(x):w1(x):r2(y):w2(y) ii) r1(y):r2(y):r3(y):w2(y):w1(y):w3(y)

    [6 marks]
    Transaction Processing and Concurrency ControlVery likelyfrom 2079 paper →

    This question has recurred in 2 of 5 years; including the board exam 1× (2079); and its topic (Transaction Processing and Concurrency Control) appears in 100% of years.

  5. 5.

    Design an ER diagram that contains at least three entities. One of the entity must be weak entity. There should be many to many relationship between the two strong entities. Use your own assumptions for other requirements. Now convert the so constructed ER diagram into equivalent database table schema. [3+3]

    [6 marks]
    Fundamental Concept of DBMSVery likelyfrom 2081 paper →

    Asked once (2081); including the board exam 1× (2081); and its topic (Fundamental Concept of DBMS) appears in 100% of years.

04The receipts

Behind the numbers

The raw evidence the predictions are computed from: marks per unit per year, syllabus weights, trends, and coverage.

Show the heatmap, topic table and coverage analysis

The receipt: marks per unit, per year

Each row is a syllabus unit, each column an exam year, each cell the marks that unit earned that year. Click any cell to see the actual questions behind it.

Marks:nonefew → many
2078
2079
2080
2081
2082
Total
U6Trends in Database Technology
42
U1Fundamental Concept of DBMS
36
U5Transaction Processing and Concurrency Control
30
U3Database Constraints and Normalization
24
U2Relational Languages and Relational Model
24
U4SQL & Query Optimization
15
U7Advanced Topic
9
#Syllabus unitProbabilityAppearedAvg marksSyllabus weightExam vs syllabusTrendQuestions
1U6Trends in Database TechnologyVery likely80%
2079208020812082
5.319%9 lecture hrsBalancedexam 15% · syllabus 19%Steadynone repeat8 total
2U1Fundamental Concept of DBMSVery likely80%
2079208020812082
3.612%6 lecture hrsOver-examinedexam 28% · syllabus 12%Steadynone repeat10 total
3U5Transaction Processing and Concurrency ControlVery likely80%
2079208020812082
512%6 lecture hrsBalancedexam 12% · syllabus 12%Steadynone repeat6 total
4U3Database Constraints and NormalizationVery likely80%
2079208020812082
4.812%6 lecture hrsOver-examinedexam 18% · syllabus 12%Fadingnone repeat5 total
5U2Relational Languages and Relational ModelVery likely80%
2079208020812082
4.815%7 lecture hrsBalancedexam 14% · syllabus 15%Risingnone repeat5 total
6U4SQL & Query OptimizationLikely60%
208020812082
512%6 lecture hrsUnder-examinedexam 6% · syllabus 12%Rising1 recurring1 total
7U7Advanced TopicVery likely60%
208020812082
317%8 lecture hrsUnder-examinedexam 8% · syllabus 17%Steadynone repeat3 total
20783 sittings
first assessmentfirst reassessmentregular
20791 sitting
board
20803 sittings
boardfirst assessmentsecond assessment
20814 sittings
boardfirst assessmentsecond assessment
20822 sittings
boardsecond assessment

Study smart, not hard

Drag the slider: studying the top 5 units in priority order covers ~86% of all observed marks.

  5. ~80% line

Lecture time vs exam marks

Where the exam pays more than the curriculum spends: ● lectures vs ● exam marks, as a share of the whole course. A long teal-leading bar = high-yield unit.

U1Fundamental Concept of DBMS
12% of lectures → 28% of markshigh yield
U3Database Constraints and Normalization
12% of lectures → 18% of markshigh yield
U6Trends in Database Technology
19% of lectures → 15% of marks
U5Transaction Processing and Concurrency Control
12% of lectures → 12% of marks
U2Relational Languages and Relational Model
15% of lectures → 14% of marks
U7Advanced Topic
17% of lectures → 8% of markslow yield
U4SQL & Query Optimization
12% of lectures → 6% of markslow yield

Topics are the official MDS 505 syllabus units. Predictions are data-driven probabilities computed from 13 past papers (2078-2082) by mapping each real question to its syllabus unit. They indicate what has historically been likely, not guaranteed questions. Always study the full syllabus.