PostgreSQL Online Test

1. What is the purpose of an index in PostgreSQL database design?

To speed up data retrieval by providing quick access to specific columns To store backup copies of data To define constraints for data integrity To define relationships between tables

2. What is the purpose of the "pg_stat_statements" extension in PostgreSQL?

To track and log executed SQL statements for analysis To provide encryption for data at rest To create user roles and permissions To optimize query performance

3. What is "logical replication" in PostgreSQL?

A method of replicating data based on changes to specific tables or columns A method for creating new databases A method for optimizing query performance A method for taking database backups

4. In PostgreSQL, what is "failover" in the context of replication?

The process of switching to a standby server if the primary server becomes unavailable The process of creating a new database The process of optimizing query performance The process of taking database backups

5. What is the purpose of PostgreSQL's "GRANT" and "REVOKE" statements in the context of security?

To assign or remove privileges on database objects to/from roles To create new tables To modify user passwords To log user activity

6. What does the "DELETE" statement in PostgreSQL do?

Removes records from a table Modifies records in a table Adds new records to a table Combines data from multiple tables

7. What is the "PostGIS" extension used for in PostgreSQL?

To enable support for geographic and geospatial data To store binary data To create read-only replicas To improve query performance

8. Which PostgreSQL tool provides a command-line interface for database administration and scripting tasks?

"psql" "pgAdmin" "pg_dump" "pgBouncer"

9. Which PostgreSQL command is used to back up a database cluster, including all databases and configuration files?

pg_basebackup pg_dump pg_copy pg_restore

10. How can you install PostgreSQL on a Linux system?

Using the 'yum install postgresql' command Downloading the Windows installer from the official website Using Homebrew on macOS Using the Chocolatey package manager on Windows

11. What is the purpose of "replication slots" in PostgreSQL?

To keep track of which changes have been received by standby servers To store backups of the database To optimize query performance To create new databases

12. What is "streaming replication" in PostgreSQL?

A method of replicating data by streaming changes from the primary to the standby server A method for optimizing query performance A method for creating new databases A method for taking database backups

13. Which SQL clause is used to pivot rows into columns in PostgreSQL?

PIVOT UNPIVOT CROSS JOIN CASE

14. Which geospatial format is supported by the "WKT" abbreviation in PostgreSQL's geospatial features?

Well-Known Text Web Key Token Web Knowledge Transfer Web Kinetic Technology

15. In PostgreSQL's geospatial data management, what is "SRID" an acronym for?

Spatial Reference IDentifier Systematic Resource Identifier Server-Request ID Secure Repository ID

16. In PostgreSQL security best practices, what does "least privilege" mean?

Providing users with the minimum level of access necessary for their tasks Creating strong database indexes Optimizing query performance Enforcing strict password requirements

17. What does "hstore" data type provide in PostgreSQL's NoSQL features?

Key-value storage for semi-structured data Text search capabilities Geospatial data storage XML data storage

18. In PostgreSQL, what is the purpose of a foreign key constraint in a table?

To ensure referential integrity between tables To create an auto-incrementing column To enforce primary key constraints To define default values for columns

19. What does a "pg_dumpall" command do in PostgreSQL backup?

It creates a backup of all PostgreSQL databases and roles It performs a full system backup of the PostgreSQL server It optimizes the database performance It copies only specific tables from a database

20. What is the primary goal of continuous archiving and point-in-time recovery (PITR) in PostgreSQL backup and restore?

To provide a way to recover the database to a specific point in time To create an exact copy of the database To optimize query performance To create daily backups