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. How many files or forks on disk will a 10Mb table with no index have?

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

No such database

Useful for creating development schemas

Useful for Postgres support Services to debug issues

3 / 20

3. Which fork is specific for unlogged tables?

Main fork

free space map

Initialization fork

visiblilty map

4 / 20

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

Dan Brown

Egor Rogov

Paul Sammy

Sam Altman

5 / 20

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

True

False

6 / 20

6. Which of below are predefined schemas?

choose 2

pg_catalog

system

public

postgres

7 / 20

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

pginit

postgres

init

postman

8 / 20

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

True

False

9 / 20

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

Main fork

visiblilty map

free space map

table map

10 / 20

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

rollback segments (RBS)

undo segments (UNDO)

online redo logs (ORL)

write-ahead log (WAL)

11 / 20

11. Tablespaces can be used to segregate data based on performance needs?

False

True

12 / 20

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

True

False

13 / 20

13. Files are logically split into pages?

False

True

14 / 20

14. What is the name of the 2 default tablespaces created after initialization?

choose 2

pg_tablespace

pg_global

pg_default

pg_temp

15 / 20

15. Which fork contains the actual table data?

free space map

table map

Main fork

visiblilty map

16 / 20

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

True

False

17 / 20

17. Users should not modify the template0 database

False

True

18 / 20

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

Schema Path

Access Path

Search Path

Directory Path

19 / 20

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

BAKE

TOAST

GROW

BREAD

20 / 20

20. What is the purpose of the template1 database?

database used for temporary tables

a template for all the other databases

No such database

regular database that you can use at your discretion

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 SQL standard specifies three isolation levels?

True

False

2 / 10

2. 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.

Use a single SQL operator

Apply explicit locks

Replace procedural code with declarative one.

3 / 10

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

Read Uncommitted

Repeatable Read

Read Committed

Serializable

4 / 10

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

True

False

5 / 10

5. 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 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.

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

6 / 10

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

False

True

7 / 10

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

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

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

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

reading data direct from memory using pg_dirt

8 / 10

8. non-repeatable read anomaly occurs when?

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.

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, another transaction modifies this row between these reads and commits the change.

9 / 10

9. Which of the below are valid Isolations Levels?

choose 2

Serializable

Rollback Read

Read Committed

Random Scatter

10 / 10

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

ACID

SAFE

HIPPA

SOC2

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. UPDATE can be regarded as which 2 separate operations?

MERGE

COMMIT

DELETE

INSERT

2 / 10

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

clog

view

heap

dump

3 / 10

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

True

False

4 / 10

4. Indexes values also support multi versioning with several versions of an index value existing at any point in time?

False

True

5 / 10

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

sequential number

xmin

checksum

backend process ID

6 / 10

6. Information about subtransactions is stored under?

PGDATA/pg_xid

PGDATA/pg_min

PGDATA/pg_subtrans

PGDATA/subtrans

7 / 10

7. When a transaction is committed Postgres uses a special <replace with answer> structure?

transaction log

redo log

commit log

archive log

8 / 10

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

True

False

9 / 10

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

False

True

10 / 10

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

xmax

xid

xtime

xmin

Your score is

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