151. Which lock allows multiple reads?
A) Shared lock
B) Exclusive lock
C) Binary lock
D) Update lock
Answer: A
Which lock allows write operation?
A) Shared lock
B) Exclusive lock
C) Read lock
D) View lock
Answer: B
Which protocol ensures serializability?
A) Locking protocol
B) Two-phase locking
C) Timestamp
D) All of these
Answer: D
Two-phase locking has:
A) One phase
B) Two phases
C) Three phases
D) No phase
Answer: B
First phase of 2PL is:
A) Shrinking
B) Growing
C) Locking
D) Unlocking
Answer: B
Second phase of 2PL is:
A) Growing
B) Shrinking
C) Locking
D) Processing
Answer: B
Which problem occurs due to concurrent transactions?
A) Deadlock
B) Anomaly
C) Inconsistency
D) All of these
Answer: D
Dirty read occurs when:
A) Reading committed data
B) Reading uncommitted data
C) Writing data
D) Deleting data
Answer: B
Lost update problem occurs when:
A) One update overwrites another
B) Data deleted
C) Data inserted
D) Data stored
Answer: A
Phantom read occurs when:
A) Same data read twice
B) New rows appear
C) Data deleted
D) Data updated
Answer: B
Which level prevents dirty reads?
A) Read Uncommitted
B) Read Committed
C) Repeatable Read
D) Serializable
Answer: B
Highest isolation level is:
A) Read Committed
B) Repeatable Read
C) Serializable
D) Read Uncommitted
Answer: C
Which level allows dirty reads?
A) Serializable
B) Read Uncommitted
C) Repeatable Read
D) Read Committed
Answer: B
Checkpoint is used in:
A) Backup
B) Recovery
C) Security
D) Indexing
Answer: B
Log file stores:
A) Data
B) Transactions
C) Queries
D) Tables
Answer: B
Which recovery technique uses logs?
A) Logging
B) Shadow paging
C) Backup
D) Replication
Answer: A
Shadow paging avoids:
A) Logs
B) Data
C) Backup
D) Queries
Answer: A
Replication means:
A) Copy data
B) Delete data
C) Update data
D) Insert data
Answer: A
Data warehouse stores:
A) Current data
B) Historical data
C) Temporary data
D) Raw data
Answer: B
OLTP is used for:
A) Analysis
B) Transactions
C) Backup
D) Reporting
Answer: B
OLAP is used for:
A) Transactions
B) Analysis
C) Data entry
D) Backup
Answer: B
Which schema is used in data warehouse?
A) Star schema
B) Tree schema
C) Flat schema
D) Graph schema
Answer: A
Fact table stores:
A) Descriptive data
B) Numeric data
C) Keys only
D) Metadata
Answer: B
Dimension table stores:
A) Numeric data
B) Descriptive data
C) Keys only
D) Index
Answer: B
Data mining is:
A) Data deletion
B) Data extraction
C) Data storage
D) Data insertion
Answer: B
Which is data mining technique?
A) Classification
B) Clustering
C) Association
D) All of these
Answer: D
Big data characteristics include:
A) Volume
B) Velocity
C) Variety
D) All of these
Answer: D
Hadoop is used for:
A) DBMS
B) Big data
C) SQL
D) Backup
Answer: B
Which language is used in Hadoop?
A) SQL
B) HiveQL
C) HTML
D) CSS
Answer: B
Data lake stores:
A) Structured data
B) Unstructured data
C) Both
D) None
Answer: C
Which is a distributed database?
A) Oracle RAC
B) MySQL
C) SQLite
D) MS Access
Answer: A
Distributed DB stores data:
A) One place
B) Multiple locations
C) Temporary
D) Local only
Answer: B
Centralized database stores data:
A) Multiple places
B) One location
C) Distributed
D) Cloud
Answer: B
Cloud database is hosted on:
A) Local server
B) Internet
C) Personal PC
D) Mobile
Answer: B
Which is cloud DB example?
A) Firebase
B) MySQL
C) SQLite
D) Access
Answer: A
Data fragmentation means:
A) Split data
B) Merge data
C) Delete data
D) Copy data
Answer: A
Horizontal fragmentation splits:
A) Columns
B) Rows
C) Tables
D) Database
Answer: B
Vertical fragmentation splits:
A) Rows
B) Columns
C) Tables
D) Files
Answer: B
Which DB ensures availability?
A) Distributed DB
B) Centralized DB
C) Flat file
D) Manual DB
Answer: A
CAP theorem includes:
A) Consistency
B) Availability
C) Partition tolerance
D) All of these
Answer: D
Which DB prioritizes availability?
A) NoSQL
B) SQL
C) Flat
D) Manual
Answer: A
Which DB prioritizes consistency?
A) Relational DB
B) NoSQL
C) Flat
D) Manual
Answer: A
Data migration means:
A) Data transfer
B) Data deletion
C) Data update
D) Data insertion
Answer: A
ETL stands for:
A) Extract Transform Load
B) Enter Transfer Load
C) Extract Transfer Load
D) Edit Transform Load
Answer: A
Which tool is used in ETL?
A) Informatica
B) MySQL
C) Oracle
D) Excel
Answer: A
Data mart is:
A) Small warehouse
B) Large DB
C) Table
D) Index
Answer: A
Which improves scalability?
A) Distributed DB
B) Centralized DB
C) Flat file
D) Manual DB
Answer: A
Scalability means:
A) Increase size
B) Reduce size
C) Delete data
D) Backup data
Answer: A
Which DB is scalable?
A) NoSQL
B) Flat file
C) Manual DB
D) Paper DB
Answer: A
200. DBMS is essential for:
A) Data management
B) Data redundancy
C) Data deletion
D) Data loss
Answer: A