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

pg_system

pg_catalog

pg_class

pg_tables

2 / 20

2. A Postgres cluster consists of 2 or more physical servers accessing one Postgres Instance?

False

True

3 / 20

3. What is the purpose of autovacuum?

Rebuilds indexes with b level greater than 2

Performs a backup of WAL logs

Deletes old logs and traces on disk

Removes stale data from tables and indexes

4 / 20

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

postman

pginit

postgres

init

5 / 20

5. Postgres by default has built in connection pooling abilities?

True

False

6 / 20

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

Access Path

Search Path

Schema Path

Directory Path

7 / 20

7. What is the purpose of wal writer?

collects usage statistics for the instance.

executes checkpoints

flushes dirty pages to disk.

writes WAL entries to disk

8 / 20

8. Which of below are predefined schemas?

choose 2

system

pg_catalog

postgres

public

9 / 20

9. What is a schema?

This is the same as a user in Postgres

The name used to refer to a super user account

Namespace that store all objects of a database

A memory area used to cache data from LRU chains

10 / 20

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

pg_tabspace

pg_tblspc

pg_symlinks

pg_tablespace

11 / 20

11. Which fork keeps track of available space within pages?

free space map

used space map

wal space map

vacuum space map

12 / 20

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

free space map

table map

visiblilty map

Main fork

13 / 20

13. Which of below are predefined schemas?

choose 3

pg_schema

pg_temp

pg_toast

information_schema

14 / 20

14. What is the name of the mechanism used to store a row bigger than a page size?

GROW

BREAD

TOAST

BAKE

15 / 20

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

False

True

16 / 20

16. What is the purpose of the template0 database?

Useful for Postgres support Services to debug issues

No such database

Useful for creating development schemas

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

17 / 20

17. The default Page size is 2k?

False

True

18 / 20

18. What is the purpose of the template1 database?

No such database

regular database that you can use at your discretion

a template for all the other databases

database used for temporary tables

19 / 20

19. How many rows in a page does Postgres aim to have before considering TOAST?

20 / 20

20. Which of the below objects can be referred to as relations?

choose 3

tables

triggers

indexes

sequences

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. A phantom read anomaly occurs when?

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

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

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.

2 / 10

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

False

True

3 / 10

3. At any moment the database system can contain several versions of one and the same row?

False

True

4 / 10

4. 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

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

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

5 / 10

5. Based on Snapshot Isolation use of MVCC which of the below are permitted?

choose 3

Read Committed

Serializable

Read Uncommitted

Repeatable Read

6 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

7 / 10

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

False

True

8 / 10

8. Which isolation level in theory could mean an application does not have to consider isolation anomalies?

Read Committed

Serializable

Repeatable Read

Read Uncommitted

9 / 10

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

False

True

10 / 10

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

SAFE

SOC2

ACID

HIPPA

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. Which 2 of the below represent transaction IDs used for row versioning?

xmax

xtime

xid

xmin

2 / 10

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

True

False

3 / 10

3. The page Special Space is located at the start of the page with highest address

False

True

4 / 10

4. Tuples can also be referred to as columns?

False

True

5 / 10

5. Postgres table physical data files are always cross compatible across platforms?

True

False

6 / 10

6. A page along with its tuples is read into the buffer cache with compression transformations to enhance cache efficiency?

True

False

7 / 10

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

COMMIT

CREATE

DELETE

INSERT

8 / 10

8. indexes do not use row versioning?

False

True

9 / 10

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

pg_current_commit_id()

pg_current_xact_id()

pg_current_id()

pg_current_xmin_id()

10 / 10

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

True

False

Your score is

Cookie	Duration	Description
cookielawinfo-checkbox-analytics	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Analytics".
cookielawinfo-checkbox-functional	11 months	The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional".
cookielawinfo-checkbox-necessary	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookies is used to store the user consent for the cookies in the category "Necessary".
cookielawinfo-checkbox-others	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Other.
cookielawinfo-checkbox-performance	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Performance".
viewed_cookie_policy	11 months	The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. It does not store any personal data.