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Unit 5: Introduction to PostgreSQL - Practice Quiz

INT222 — Advanced Web Development 50 Questions
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1 What type of database management system is PostgreSQL classified as?

A. Object-Relational Database Management System (ORDBMS)
B. Network Database
C. Flat File Database
D. Hierarchical Database

2 Which mechanism does PostgreSQL use to handle concurrency without read locks blocking write locks?

A. Optimistic Locking
B. Table Locking
C. MVCC (Multi-Version Concurrency Control)
D. Two-Phase Locking

3 What is the default TCP port that PostgreSQL listens on?

A. 3306
B. 8080
C. 5432
D. 1521

4 What is the name of the interactive terminal-based command-line tool for PostgreSQL?

A. psql
B. pgAdmin
C. pg_terminal
D. sqlcmd

5 Which configuration file is primarily responsible for controlling client authentication in PostgreSQL?

A. postgresql.conf
B. pg_hba.conf
C. pg_ident.conf
D. config.json

6 What is the default superuser account created during PostgreSQL installation?

A. sa
B. root
C. postgres
D. admin

7 Which command inside the psql interface is used to list all databases?

A. \list
B. SHOW DATABASES;
C. Both A and B
D. \l

8 Which data type in PostgreSQL is best suited for storing JSON data with indexing capabilities?

A. JSONB
B. JSON
C. TEXT
D. VARCHAR

9 Which SQL statement is used to create a new database in PostgreSQL?

A. INIT DATABASE name;
B. NEW DATABASE name;
C. MAKE DATABASE name;
D. CREATE DATABASE name;

10 What does the acronym WAL stand for in the context of PostgreSQL architecture?

A. Web Application Layer
B. Write-Ahead Logging
C. Write-After Log
D. Wide-Area Latency

11 Which command allows you to connect to a specific database from within the psql prompt?

A. \connect dbname
B. Both A and B
C. \c dbname
D. \use dbname

12 To remove a table and all its data from the database, which command is used?

A. DROP TABLE
B. DELETE TABLE
C. REMOVE TABLE
D. ERASE TABLE

13 Which PostgreSQL data type is an auto-incrementing integer typically used for primary keys?

A. NUMERIC
B. SERIAL
C. AUTO_INT
D. INT

14 What is the purpose of the 'TRUNCATE' command?

A. To delete specific rows based on a condition
B. To delete all rows quickly without logging individual row deletions
C. To minify the database size
D. To drop the table structure

15 Which constraint ensures that a column cannot contain NULL values?

A. NOT NULL
B. CHECK
C. UNIQUE
D. PRIMARY KEY

16 How do you rename an existing table 'users' to 'customers' in PostgreSQL?

A. MODIFY TABLE users RENAME customers;
B. RENAME TABLE users TO customers;
C. UPDATE TABLE users SET NAME = customers;
D. ALTER TABLE users RENAME TO customers;

17 Which operator is used for pattern matching with wildcards in a WHERE clause?

A. LIKE
B. MATCH
C. SAME
D. =

18 In the context of the LIKE operator, what does the '%' wildcard represent?

A. Exactly one character
B. A numeric digit
C. Zero or more characters
D. A NULL value

19 Which SQL clause is used to filter records that meet a specified condition?

A. WHERE
B. HAVING
C. ORDER BY
D. GROUP BY

20 What is the correct syntax to insert a new record into the 'students' table?

A. ADD TO students VALUES (1, 'John');
B. INSERT INTO students (id, name) VALUES (1, 'John');
C. UPDATE students ADD (1, 'John');
D. INSERT students SET id=1, name='John';

21 How can you retrieve all columns from the 'employees' table?

A. SELECT ALL FROM employees;
B. SELECT * FROM employees;
C. GET * FROM employees;
D. FETCH employees;

22 Which clause allows you to limit the number of rows returned by a query?

A. LIMIT
B. TOP
C. ROWNUM
D. STOP

23 Which command allows you to skip a specific number of rows before returning the result set?

A. SKIP
B. JUMP
C. OFFSET
D. NEXT

24 What is the correct syntax to update the email of a user with id 5?

A. UPDATE users SET email = 'new@test.com' WHERE id = 5;
B. CHANGE users email = 'new@test.com' WHERE id = 5;
C. SET users.email = 'new@test.com' WHERE id = 5;
D. MODIFY users SET email = 'new@test.com' WHERE id = 5;

25 What happens if you run a DELETE FROM table_name command without a WHERE clause?

A. It deletes the first row.
B. It throws a syntax error.
C. It deletes all rows in the table.
D. It deletes the table structure.

26 Which keyword is used to return data immediately after an INSERT, UPDATE, or DELETE operation in PostgreSQL?

A. RETURNING
B. BACK
C. OUTPUT
D. RETURN

27 Which PostgreSQL data type stores both date and time?

A. DATETIME
B. DATE
C. TIMESTAMP
D. TIME

28 Which command is used to modify the structure of an existing table, such as adding a column?

A. ALTER TABLE
B. CHANGE TABLE
C. UPDATE TABLE
D. MODIFY TABLE

29 To ensure a column's value is unique across the entire table, which constraint should be used?

A. UNIQUE
B. PRIMARY
C. DISTINCT
D. SINGLE

30 Which operator is used to combine string values in PostgreSQL?

A. CONCAT()
B. +
C. &
D. ||

31 How do you sort the result set in descending order?

A. SORT BY column_name DESC
B. ORDER BY column_name DESC
C. ORDER BY column_name ASC
D. GROUP BY column_name DESC

32 Which function is used to count the number of rows in a selection?

A. ADD()
B. SUM()
C. COUNT()
D. TOTAL()

33 What is the purpose of the DISTINCT keyword in a SELECT statement?

A. To filter null values
B. To sort results
C. To remove duplicate values from the result set
D. To limit results

34 Which of the following is a correct command to add a new column 'age' of type integer to table 'people'?

A. UPDATE TABLE people ADD age INTEGER;
B. ALTER TABLE people ADD COLUMN age INTEGER;
C. ALTER people ADD age INTEGER;
D. INSERT COLUMN age INTEGER INTO people;

35 What does the psql command '\d table_name' do?

A. Duplicates the table
B. Deletes the table
C. Describes the table structure
D. Downloads the table

36 Which logical operator is used to display a record if any of the conditions separated by it are true?

A. OR
B. NOT
C. AND
D. XOR

37 How do you check for a NULL value in a WHERE clause?

A. IS NULL
B. == NULL
C. = NULL
D. EQUALS NULL

38 Which PostgreSQL tool is a popular open-source GUI for database management?

A. Compass
B. phpMyAdmin
C. Workbench
D. pgAdmin

39 What does the PRIMARY KEY constraint imply?

A. NOT NULL only
B. UNIQUE only
C. Just an index
D. Both UNIQUE and NOT NULL

40 Which command allows you to quit the psql terminal?

A. \q
B. quit
C. exit
D. logout

41 Which clause is used to filter groups of rows created by GROUP BY?

A. HAVING
B. LIMIT
C. WHERE
D. FILTER

42 Which statement is used to delete an entire database?

A. DROP DATABASE name;
B. TRUNCATE DATABASE name;
C. REMOVE DATABASE name;
D. DELETE DATABASE name;

43 What is the purpose of the 'IN' operator?

A. To specify multiple possible values for a column
B. To search text patterns
C. To check for NULL
D. To specify a range

44 Which data type would be most appropriate for a True/False value?

A. BOOLEAN
B. INT
C. VARCHAR(1)
D. BINARY

45 What does the BETWEEN operator select?

A. Values that are null
B. Values within a given range
C. Values that match a list
D. Values that are distinct

46 To create a foreign key, which table is modified?

A. The child table
B. Both tables
C. The system table
D. The parent table

47 Which command is used to remove a specific column from a table?

A. DROP COLUMN ... FROM ...
B. ALTER TABLE ... REMOVE COLUMN ...
C. ALTER TABLE ... DROP COLUMN ...
D. ALTER TABLE ... DELETE COLUMN ...

48 Which basic SQL command is NOT part of CRUD operations?

A. CREATE
B. SELECT
C. INSERT
D. UPDATE

49 What is the default sort order if ASC or DESC is not specified in ORDER BY?

A. Random
B. Descending
C. Insertion Order
D. Ascending

50 Which character is used to denote a parameter/variable placeholder in a prepared statement in psql (e.g., $1, $2)?

A. :
B. ?
C. @
D. $
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