PostgreSQL Online Test

1. What is the primary purpose of "ST_GeomFromText" in PostgreSQL's geospatial features?

To create a geometry from Well-Known Text (WKT) representation To create a new database To optimize query performance To manage user roles

2. What is the purpose of "connection pooling" in PostgreSQL performance tuning?

To reuse database connections, reducing connection overhead To store data redundantly for backup To combine multiple databases into a single pool To increase the number of available connections

3. What does the "BEGIN" statement do in PostgreSQL transactions?

Initiates a new transaction Commits the transaction to save changes Rolls back the transaction Locks the database for exclusive access

4. Which of the following statements about connection pooling in PostgreSQL is true?

It helps manage and control concurrent connections more effectively It doesn't have any impact on database performance It is primarily used to increase the number of concurrent connections It encrypts data during transmission

5. Which SQL statement is used to filter rows in a table based on a specified condition?

WHERE ORDER BY GROUP BY HAVING

6. 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

7. What is the role of the 'pg_ctl' utility in PostgreSQL?

It manages PostgreSQL clusters It's used to create databases It imports data into PostgreSQL It runs SQL queries

8. In PostgreSQL, what does the term "index" refer to in the context of performance tuning?

A data structure that provides quick access to specific columns A special table that stores summary information A file used for database backups A data type used for storing integers

9. In PostgreSQL, what is the benefit of using table partitioning to manage large datasets?

It improves query performance and simplifies data maintenance It increases the complexity of SQL queries It reduces the number of connections to the database It encrypts data during transmission

10. What does the "hstore" extension in PostgreSQL allow you to store and manage?

Key-value pairs Images Arrays XML data

11. In PostgreSQL, what is the purpose of a trigger in a database schema?

To automatically execute a predefined action when certain database events occur To enforce primary key constraints To create views for data retrieval To define relationships between tables

12. Which PostgreSQL extension is commonly used for data warehousing to manage large datasets?

"pgCube" "pgETL" "pgPartitions" "pgBouncer"

13. In PostgreSQL, what is the purpose of the 'psql' command?

It connects to the PostgreSQL database It generates reports It encrypts data It compiles PL/pgSQL functions

14. What is the purpose of "OLAP" in data warehousing with PostgreSQL?

Online Analytical Processing (OLAP) is used for complex, interactive analysis of data in a data warehouse To create physical backups of the data warehouse To manage database connections To encrypt data during transmission

15. Which tool is used for database migration and data synchronization in PostgreSQL?

"pglogical" "pg_dump" "psql" "pgBouncer"

16. 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

17. What is the "write-ahead log" (WAL) in PostgreSQL replication?

A log that records all changes made to the database, used for replication and recovery A log that stores query plans A log that tracks database connections A log for taking database backups

18. Which PostgreSQL configuration parameter allows restricting the IP addresses from which the database server can accept connections?

"listen_addresses" "shared_buffers" "max_connections" "random_page_cost"

19. What is a recursive common table expression (RCTE) in PostgreSQL used for?

To handle hierarchical data and recursive queries To create temporary tables To join multiple tables To define primary keys

20. In PostgreSQL, what is the term for a standby server that is in "hot standby" mode, ready to take over as the primary?

Hot Standby Active Standby Primary Standby Warm Standby