MCQs on Getting Started with PostgreSQL | PostgreSQL Database
Enhance your PostgreSQL skills with this comprehensive collection of 30 multiple-choice questions. Covering connection methods, basic commands, database creation/deletion, and schema management, these questions are perfect for learners and professionals alike.
Topics Covered:
- Connecting to PostgreSQL using psql
- Basic psql Commands
- Creating and Deleting Databases
- Understanding Schemas
MCQs on Getting Started with PostgreSQL
Connecting to PostgreSQL using psql
- Which command is used to connect to a PostgreSQL database using psql?
- A) psql -c
- B) psql -U <username> -d <database>
- C) connectdb -U <username>
- D) postgre -U <username>
- What is the default port number for PostgreSQL?
- A) 5432
- B) 3306
- C) 1521
- D) 1526
- Which environment variable can be set to store the PostgreSQL username for psql?
- A) PG_USERNAME
- B) PGUSER
- C) PGDBUSER
- D) USER_PGSQL
- How do you connect to a database named testdb as user admin in psql?
- A) psql –database=testdb –username=admin
- B) psql -d testdb -U admin
- C) psql -db testdb –user admin
- D) connect testdb as admin
- If the PostgreSQL server is running on a non-default port, how can it be specified in the psql command?
- A) psql –port=<port_number>
- B) psql -p <port_number>
- C) psql –connect <port_number>
- D) psql -t <port_number>
Basic psql Commands
- Which psql command is used to list all databases?
- A) \ld
- B) \dt
- C) \l
- D) \db
- How can you switch to another database in psql?
- A) switch <database_name>
- B) connect <database_name>
- C) \c <database_name>
- D) \switch <database_name>
- Which psql command is used to display help for SQL commands?
- A) \h
- B) \help
- C) \info
- D) \commands
- What does the
\dcommand do in psql?- A) Lists all schemas
- B) Lists all tables
- C) Describes the structure of a table
- D) Deletes a table
- How can you exit the psql terminal?
- A) exit
- B) quit
- C) \q
- D) \exit
- Which psql command is used to display all tables in the current database?
- A) \list-tables
- B) \d
- C) \dt
- D) \table-list
- What is the shortcut to run the last executed SQL command again in psql?
- A) \repeat
- B) !!
- C) \g
- D) !!<command_id>
- How do you display the current PostgreSQL version in psql?
- A) SELECT pg_version();
- B) SHOW version;
- C) \v
- D) SELECT version();
- What is the purpose of the
\timingcommand in psql?- A) Displays the time taken to execute queries
- B) Shows server connection time
- C) Synchronizes server and client time
- D) None of the above
- Which command lists all roles in a PostgreSQL database?
- A) \roles
- B) \du
- C) \list-roles
- D) SHOW ROLES
Creating and Deleting Databases
- Which SQL command is used to create a database in PostgreSQL?
- A) CREATE DATABASE <db_name>;
- B) INIT DATABASE <db_name>;
- C) NEW DATABASE <db_name>;
- D) DATABASE CREATE <db_name>;
- Which role must a user have to create a database in PostgreSQL?
- A) Superuser
- B) Database Owner
- C) Database Administrator
- D) Creator
- How do you delete a database in PostgreSQL?
- A) DROP DATABASE <db_name>;
- B) DELETE DATABASE <db_name>;
- C) REMOVE DATABASE <db_name>;
- D) CLEAR DATABASE <db_name>;
- Which psql command can confirm the successful creation of a database?
- A) \list
- B) \db-status
- C) \show-databases
- D) SELECT db_name;
- Can you delete a database while connected to it in psql?
- A) Yes
- B) No
- C) Only with sufficient privileges
- D) It depends on the PostgreSQL version
Understanding Schemas
- What is the purpose of schemas in PostgreSQL?
- A) Organize tables and other database objects
- B) Improve query performance
- C) Manage database connections
- D) Define user roles
- What is the default schema in a PostgreSQL database?
- A) default_schema
- B) base
- C) public
- D) root
- How do you list all schemas in the current database using psql?
- A) \ds
- B) \dt
- C) \dn
- D) \schemas
- Which command is used to create a new schema in PostgreSQL?
- A) CREATE NEW SCHEMA <schema_name>;
- B) NEW SCHEMA <schema_name>;
- C) CREATE SCHEMA <schema_name>;
- D) INIT SCHEMA <schema_name>;
- What happens if a schema is dropped in PostgreSQL?
- A) The database is reset
- B) All objects in the schema are removed
- C) The schema is archived
- D) Nothing happens
- Can multiple schemas in PostgreSQL contain objects with the same name?
- A) Yes
- B) No
- C) Only for tables
- D) Only for indexes
- Which command is used to delete a schema in PostgreSQL?
- A) REMOVE SCHEMA <schema_name>;
- B) DROP SCHEMA <schema_name>;
- C) DELETE SCHEMA <schema_name>;
- D) CLEAR SCHEMA <schema_name>;
- How can you change the search path for schemas in PostgreSQL?
- A) SET SCHEMA_PATH ‘<schema>’;
- B) ALTER SCHEMA SEARCH ‘<schema>’;
- C) SET search_path TO ‘<schema>’;
- D) CHANGE SCHEMA ‘<schema>’;
- Which system catalog stores information about schemas in PostgreSQL?
- A) pg_schemas
- B) pg_namespace
- C) pg_catalog_schema
- D) schema_list
- How can you rename an existing schema in PostgreSQL?
- A) RENAME SCHEMA <old_name> TO <new_name>;
- B) ALTER SCHEMA <old_name> RENAME TO <new_name>;
- C) UPDATE SCHEMA <old_name> TO <new_name>;
- D) MODIFY SCHEMA <old_name> TO <new_name>;
Answer Key
| Qno | Answer |
|---|---|
| 1 | B) psql -U <username> -d <database> |
| 2 | A) 5432 |
| 3 | B) PGUSER |
| 4 | B) psql -d testdb -U admin |
| 5 | B) psql -p <port_number> |
| 6 | C) \l |
| 7 | C) \c <database_name> |
| 8 | A) \h |
| 9 | C) Describes the structure of a table |
| 10 | C) \q |
| 11 | C) \dt |
| 12 | C) \g |
| 13 | D) SELECT version(); |
| 14 | A) Displays the time taken to execute queries |
| 15 | B) \du |
| 16 | A) CREATE DATABASE <db_name>; |
| 17 | A) Superuser |
| 18 | A) DROP DATABASE <db_name>; |
| 19 | A) \list |
| 20 | B) No |
| 21 | A) Organize tables and other database objects |
| 22 | C) public |
| 23 | C) \dn |
| 24 | C) CREATE SCHEMA <schema_name>; |
| 25 | B) All objects in the schema are removed |
| 26 | A) Yes |
| 27 | B) DROP SCHEMA <schema_name>; |
| 28 | C) SET search_path TO ‘<schema>’; |
| 29 | B) pg_namespace |
| 30 | B) ALTER SCHEMA <old_name> RENAME TO <new_name>; |