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

True

False

2 / 20

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

True

False

3 / 20

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

False

True

4 / 20

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

pg_tablespace

pg_tblspc

pg_symlinks

pg_tabspace

5 / 20

5. What is the purpose of the visibility map?

provides an audit trail for the database

provides the data decryption key

shows a page to be vacuumed or frozen

shows referential relationships for tables

6 / 20

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

7 / 20

7. System Catalog tables begin with which prefix?

dba_

cat_

pg_

sys_

8 / 20

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

write-ahead log (WAL)

undo segments (UNDO)

rollback segments (RBS)

online redo logs (ORL)

9 / 20

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

True

False

10 / 20

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

PGBASE

PGTIPS

PGCORE

PGDATA

11 / 20

11. Who is the Author of the Postgres 14 Internals book?

Dan Brown

Egor Rogov

Sam Altman

Paul Sammy

12 / 20

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

TOAST

GROW

BAKE

BREAD

13 / 20

13. Which fork contains the actual table data?

free space map

table map

visiblilty map

Main fork

14 / 20

14. What is the purpose of the public schema?

schema used for heterogeneous replication

default schema for user objects

no such schema

restricted schema for postgres internal usage only

15 / 20

15. Tablespaces are used to define physical data layout?

True

False

16 / 20

16. Which of below are predefined schemas?

choose 3

pg_toast

pg_temp

pg_schema

information_schema

17 / 20

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

False

True

18 / 20

18. What is the purpose of the template1 database?

regular database that you can use at your discretion

No such database

database used for temporary tables

a template for all the other databases

19 / 20

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

visiblilty map

Main fork

free space map

table map

20 / 20

20. What is the name of the catalog that stores metadata for all cluster objects?

Sysaux Catalog

Sys Catalog

System Catalog

Sysasm Catalog

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. non-repeatable read anomaly occurs when?

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

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.

2 / 10

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

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

reading data direct from memory using pg_dirt

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

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

3 / 10

3. What are some of database features we can use to avoid a non repeatable read?

Select more than 1 answer below:

Issues a rollback after the commit to satisfy repeatable read.

Replace procedural code with declarative one.

Apply explicit locks

Use a single SQL operator

4 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

5 / 10

5. Which of the below are valid Isolations Levels?

choose 2

Serializable

Rollback Read

Random Scatter

Read Committed

6 / 10

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

ACID

HIPPA

SAFE

SOC2

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?

Serializable

Read Uncommitted

Repeatable Read

Read Committed

9 / 10

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

True

False

10 / 10

10. A phantom read anomaly occurs when?

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 also queries this same data.

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

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. What does an Item Pointer contain?

choose 3

tuple status

tuple offset from the start of the page

tuple length

tuple xid

2 / 10

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

False

True

3 / 10

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

Each pointer uses 4 bytes

Each pointer uses 8 bytes

stored in PGDATA/itemptr directory

Also know as the pages table of contents

4 / 10

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

True

False

5 / 10

5. Which 2 items does a Virtual XID consist of?

backend process ID

sequential number

checksum

xmin

6 / 10

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

pageheadinfo

pageinspect

pagedetect

pagesize

7 / 10

7. indexes do not use row versioning?

True

False

8 / 10

8. Information about subtransactions is stored under?

PGDATA/pg_subtrans

PGDATA/pg_xid

PGDATA/subtrans

PGDATA/pg_min

9 / 10

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

False

True

10 / 10

10. Page free space can often become fragmented?

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.