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 a schema?

A memory area used to cache data from LRU chains

This is the same as a user in Postgres

Namespace that store all objects of a database

The name used to refer to a super user account

2 / 20

2. Tablespaces are used to define physical data layout?

False

True

3 / 20

3. What is the purpose of the template0 database?

Useful for creating development schemas

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

Useful for Postgres support Services to debug issues

No such database

4 / 20

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

pg_symlinks

pg_tabspace

pg_tablespace

pg_tblspc

5 / 20

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

GROW

BREAD

BAKE

TOAST

6 / 20

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

CreateCluster

CreatePGC

StartNewPG

Initialize

7 / 20

7. The default Page size is 2k?

True

False

8 / 20

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

False

True

9 / 20

9. What is the purpose of the postgres database?

No such database

a template for all the other database

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

regular database that you can use at your discretion

10 / 20

10. What is the purpose of the template1 database?

No such database

a template for all the other databases

database used for temporary tables

regular database that you can use at your discretion

11 / 20

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

rollback segments (RBS)

write-ahead log (WAL)

undo segments (UNDO)

online redo logs (ORL)

12 / 20

12. What is the point of the pg_global tablespace?

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

stores temporary tables that are common to the whole cluster

13 / 20

13. Which 3 databases exist directly after cluster initialization?

choose 3 options

template0

postgres

template1

sysaux

14 / 20

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

False

True

15 / 20

15. What is the purpose of the visibility map?

shows a page to be vacuumed or frozen

shows referential relationships for tables

provides the data decryption key

provides an audit trail for the database

16 / 20

16. Which fork contains the actual table data?

visiblilty map

Main fork

table map

free space map

17 / 20

17. Files are logically split into pages?

True

False

18 / 20

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

True

False

19 / 20

19. Users should not modify the template0 database

True

False

20 / 20

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

pg_catalog

pg_system

pg_tables

pg_class

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. Which of the below are valid Isolations Levels?

choose 2

Serializable

Read Committed

Rollback Read

Random Scatter

2 / 10

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

SAFE

SOC2

HIPPA

ACID

3 / 10

3. Which parameters sets the database default isolation level?

transaction_isolation_level

active_transaction_isolation

default_transaction_isolation

default_isolation_level

4 / 10

4. 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 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 once and modifies this row and commits the change.

5 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

6 / 10

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

False

True

7 / 10

7. 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.

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

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

8 / 10

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

True

False

9 / 10

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

True

False

10 / 10

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

False

True

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 of the below are true about a Pages Item Pointer?

Each pointer uses 8 bytes

Each pointer uses 4 bytes

stored in PGDATA/itemptr directory

Also know as the pages table of contents

2 / 10

2. status of a subtransaction is written into CLOG?

False

True

3 / 10

3. To identify different versions of one and the same row, PostgreSQL marks each of them with which two value?

xmin

xmas

xmax

xid

4 / 10

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

False

True

5 / 10

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

pageheadinfo

pagesize

pageinspect

pagedetect

6 / 10

6. In Postgres, tables are often referred to as which of the below?

heap

dump

clog

view

7 / 10

7. indexes do not use row versioning?

False

True

8 / 10

8. Page free space can often become fragmented?

True

False

9 / 10

9. CLOG files are stored in which directory?

PGDATA/pg_clog

PGDATA/pg_xact

PGDATA/pg_commit

PGDATA/clog

10 / 10

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

False

True

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.