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. The pg_default tablespace should never be used to create user tables?

False

True

2 / 20

2. 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

3 / 20

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

True

False

4 / 20

4. What is the name of the directory that contains the files related to the Postgres cluster?

PGDATA

PGTIPS

PGCORE

PGBASE

5 / 20

5. What is the purpose of autovacuum?

Removes stale data from tables and indexes

Performs a backup of WAL logs

Deletes old logs and traces on disk

Rebuilds indexes with b level greater than 2

6 / 20

6. Which fork contains the actual table data?

table map

Main fork

visiblilty map

free space map

7 / 20

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

TOAST

GROW

BAKE

BREAD

8 / 20

8. What is the purpose of wal writer?

flushes dirty pages to disk.

collects usage statistics for the instance.

writes WAL entries to disk

executes checkpoints

9 / 20

9. What command is used to create the Postgres cluster?

Initialize

StartNewPG

CreatePGC

CreateCluster

10 / 20

10. What is the purpose of the postgres database?

a template for all the other database

No such database

regular database that you can use at your discretion

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

11 / 20

11. System Catalog tables begin with which prefix?

dba_

sys_

pg_

cat_

12 / 20

12. What is the purpose of the public schema?

restricted schema for postgres internal usage only

default schema for user objects

no such schema

schema used for heterogeneous replication

13 / 20

13. What is the purpose of the template0 database?

No such database

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

Useful for Postgres support Services to debug issues

Useful for creating development schemas

14 / 20

14. To be able to restore data consistency, Postgres maintains

online redo logs (ORL)

write-ahead log (WAL)

undo segments (UNDO)

rollback segments (RBS)

15 / 20

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

choose 3

sequences

indexes

tables

triggers

16 / 20

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

17 / 20

17. Each tablespaces can only be assigned for use by one database

False

True

18 / 20

18. The information_schema schema provides information on Postgres release notes?

True

False

19 / 20

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

postgres

postman

pginit

init

20 / 20

20. A schema can belong to more than one database?

True

False

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

False

True

2 / 10

2. What is the default Isolation Level?

Read Committed

Serializable

Repeatable Read

Read Uncommitted

3 / 10

3. Which parameters sets the database default isolation level?

active_transaction_isolation

default_transaction_isolation

default_isolation_level

transaction_isolation_level

4 / 10

4. A phantom read anomaly occurs when?

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.

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 also queries this same data.

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

5 / 10

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

True

False

6 / 10

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

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

CREATE EXTENSTION REPEATABLE_READ;

7 / 10

7. non-repeatable read anomaly occurs when?

A transaction reads one and the same row once, another transaction modifies this row between these reads and commits the change.

A transaction reads one and the same row twice, another transaction modifies this row between these reads issue a rollback.

A transaction reads one and the same row twice, another transaction modifies this row between these reads and commits the change.

A transaction reads one and the same row once and modifies this row and commits the change.

8 / 10

8. Which of the below are valid Isolations Levels?

choose 2

Random Scatter

Rollback Read

Read Committed

Serializable

9 / 10

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

choose 3

Repeatable Read

Read Committed

Serializable

Read Uncommitted

10 / 10

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

SOC2

ACID

SAFE

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

True

False

2 / 10

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

xid

xtime

xmax

xmin

3 / 10

3. indexes do not use row versioning?

True

False

4 / 10

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

True

False

5 / 10

5. Information about subtransactions is stored under?

PGDATA/subtrans

PGDATA/pg_min

PGDATA/pg_xid

PGDATA/pg_subtrans

6 / 10

6. virtual IDs exist only in PGDATA/pg_vxid when not cached?

True

False

7 / 10

7. Which of the below are true about a Pages Item Pointer?

Each pointer uses 8 bytes

Also know as the pages table of contents

Each pointer uses 4 bytes

stored in PGDATA/itemptr directory

8 / 10

8. CLOG contains how many bits for each transaction?

9 / 10

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

pagedetect

pageinspect

pagesize

pageheadinfo

10 / 10

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

DELETE

COMMIT

INSERT

CREATE

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.