PostgreSQL Online Test

1. What is the purpose of "connection pooling" in PostgreSQL for managing large datasets?

To efficiently manage and reuse database connections, reducing overhead To increase the complexity of SQL queries To encrypt data during transmission To create new databases

2. What is the purpose of connection pool maintenance in PostgreSQL?

To monitor and manage the pool's connections, ensuring their availability and efficiency To encrypt data during transmission To optimize query performance To create new databases

3. What is the purpose of a "pg_receivewal" command in PostgreSQL?

To stream Write-Ahead Logs (WAL) from a primary to a standby server To create a backup of the database To optimize query performance To restore a database from a backup

4. Which authentication method in PostgreSQL requires a client to provide a valid username and password for access?

Password authentication Certificate authentication Trust authentication LDAP authentication

5. In PostgreSQL, what is a "nested transaction"?

A transaction within another transaction A read-only transaction A transaction with multiple savepoints A transaction involving multiple databases

6. What is the default port number for PostgreSQL?

5432 3306 1521 27017

7. What is the primary purpose of a data warehouse in the context of PostgreSQL?

To store and consolidate historical data for analysis and reporting To create new databases To optimize query performance To manage user roles

8. What does the "pg_trgm" extension provide in PostgreSQL for managing large datasets?

Text similarity and full-text search capabilities Data encryption Role-based access control Multi-factor authentication

9. Which PostgreSQL authentication method allows access without a password but is restricted to local connections on Unix-like systems?

peer md5 trust scram-sha-256

10. What is the purpose of the "pg_hba.conf" file in PostgreSQL?

To define access control rules for client connections To store user passwords To log database queries To define table schemas

11. What PostgreSQL extension provides additional NoSQL-like features, such as key-value store and document storage?

"hstore" "pgCube" "cstore_fdw" "hstore_fdw"

12. What is the purpose of "GIN" and "GiST" indexing methods in PostgreSQL's NoSQL support?

To optimize querying and indexing of semi-structured data To enforce strong password requirements To create new databases To manage user roles

13. 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

14. 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

15. What does the "fact table" represent in a star schema of a data warehouse?

It contains measures and numeric data for analysis It stores user access logs It creates new databases It enforces strong password requirements

16. What happens to a database connection when a client application disconnects from the database in a connection pool setup?

The connection is returned to the pool for reuse The connection is permanently closed The connection is encrypted The connection remains cached

17. Which PostgreSQL extension is used to provide enhanced geospatial functions and data types for advanced GIS applications?

"PostGIS" "pgBouncer" "pg_dump" "psql"

18. Which PostgreSQL extension is used to implement full-text search capabilities?

"pg_trgm" "hstore" "uuid-ossp" "PostGIS"

19. Which PostgreSQL data type is commonly used to store geospatial data for GIS applications?

"Geometry" "VARCHAR" "INTEGER" "TIMESTAMP"

20. What is a database view in PostgreSQL?

A virtual table that is based on the result of a SELECT query A schema that groups related tables together A way to create user accounts and roles A system-generated unique identifier for a row