Postgres Quiz Archive

You have 200 seconds to answer 20 Random questions so think fast!

You will need to score 80% or over to pass!

Created by

Paul Sammy

PostgreSQL 14 Internals Chapter 1

A quiz to test the knowledge of those reading and learning from Postgres 14 Internals book by Egor Rogov, covering topics in Chapter 1.

1 / 20

1. Which of below are predefined schemas?

choose 2

public

system

pg_catalog

postgres

2 / 20

2. What is the purpose of the template0 database?

Useful for restoring data from a logical backup or creating a database with a different encoding

Useful for creating development schemas

Useful for Postgres support Services to debug issues

No such database

3 / 20

3. Postgres uses a thread based process model?

True

False

4 / 20

4. If we create a new tablespace which directory will symbolic links be created from?

pg_tabspace

pg_tablespace

pg_symlinks

pg_tblspc

5 / 20

5. Which of below are predefined schemas?

choose 3

pg_temp

pg_schema

information_schema

pg_toast

6 / 20

6. Files are logically split into pages?

False

True

7 / 20

7. What is another name for the postgres process?

aurora

masterprocess

postmanager

postmaster

8 / 20

8. Tablespaces are used to define physical data layout?

True

False

9 / 20

9. What is the process first launched at server start?

postman

pginit

init

postgres

10 / 20

10. What is the purpose of the template1 database?

database used for temporary tables

No such database

a template for all the other databases

regular database that you can use at your discretion

11 / 20

11. pg_catalog schema is used to store system catalog tables?

False

True

12 / 20

12. To understand each other, a client and a server must use one and the same interfacing protocol?

False

True

13 / 20

13. What is the point of the pg_global tablespace?

stores temporary tables that are common to the whole cluster

stores WAL logs used for global replication

stores system catalog objects that are common to the whole cluster

stores user tables that are common to the whole cluster

14 / 20

14. Some System Catalog tables are common to all databases in the cluster?

True

False

15 / 20

15. How does Postgres know which schema to use if not specified?

Access Path

Search Path

Directory Path

Schema Path

16 / 20

16. Postgres server spawns a new backend session for each connection?

False

True

17 / 20

17. What is the name of the system catalog table for relations?

pg_class

pg_catalog

pg_tables

pg_system

18 / 20

18. What 3 files/forks as a minimum make up a table on disk?

visiblilty map

Main fork

free space map

table map

19 / 20

19. What is the default standard size for a fork file?

1GB

1MB

5GB

5MB

20 / 20

20. What is the purpose of the visibility map?

provides the data decryption key

shows referential relationships for tables

provides an audit trail for the database

shows a page to be vacuumed or frozen

Your score is

Created by

Paul Sammy

PostgreSQL 14 Internals Chapter 2

A quiz to test the knowledge of those reading and learning from Postgres 14 Internals book by Egor Rogov, covering topics in Chapter 2.

1 / 10

1. The more locks a transaction acquires, the better it is isolated from other transactions?

False

True

2 / 10

2. Data Consistency is best handled at the application layer rather than at the database layer?

False

True

3 / 10

3. Which of the below are valid Isolations Levels?

choose 2

Rollback Read

Read Committed

Random Scatter

Serializable

4 / 10

4. A phantom read anomaly occurs when?

A transactions inserts a null value into a not null columns and commits

The same transaction executes two identical queries returning a set of rows that satisfy a particular condition, while another transaction adds some other rows satisfying this condition and commits.

The same transaction executes two identical queries returning a set of rows that satisfy a particular condition, while another transaction also queries this same data.

The same transactions issues a commit, then a rollback to restore data to its original value

5 / 10

5. which of the below statements will start a transaction as Read Repeatable?

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

6 / 10

6. Snapshot isolation is preferred but increases the number of required locks?

True

False

7 / 10

7. What is the default Isolation Level?

Repeatable Read

Read Committed

Read Uncommitted

Serializable

8 / 10

8. Which of the below would best describe a dirty read?

a session being able to see commited data altered by another session

reading data direct from memory using pg_dirt

reading the data directly from file using a text editor such as vi or notepad

a session being able to see uncommited data altered by another session

9 / 10

9. What is the acronym used for the attributes that ensure Data consistency, integrity and durability?

SOC2

ACID

SAFE

HIPPA

10 / 10

10. Lost updates are forbidden by the standard at all isolation levels?

True

False

Your score is

Created by

Paul Sammy

PostgreSQL 14 Internals Chapter 3

A quiz to test the knowledge of those reading and learning from Postgres 14 Internals book by Egor Rogov, covering topics in Chapter 3.

1 / 10

1. index row headers like table row headers contain xmin and xmax fields?

True

False

2 / 10

2. Which function can we use to find the current transaction ID?

pg_current_commit_id()

pg_current_id()

pg_current_xact_id()

pg_current_xmin_id()

3 / 10

3. Page header sizes can be easily displayed using the <choose from answers> extension

pagesize

pageheadinfo

pageinspect

pagedetect

4 / 10

4. psql provides a special mode that allows you to continue a transaction after a failure?

False

True

5 / 10

5. If a transaction aborts, all page changes are reverted(rolled back) in place?

True

False

6 / 10

6. status of a subtransaction is written into CLOG?

True

False

7 / 10

7. Page free space can often become fragmented?

True

False

8 / 10

8. at any one time Postgres can have several versions of a row?

False

True

9 / 10

9. When a row is created, its xmin value is set to the transaction ID of which command?

COMMIT

CREATE

DELETE

INSERT

10 / 10

10. The page header stores checksum and the sizes of the other parts of the page?

True

False

Your score is

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