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

False

True

2 / 20

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

True

False

3 / 20

3. It is the postmasters job to listener for incoming connections?

False

True

4 / 20

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

Initialize

StartNewPG

CreatePGC

CreateCluster

5 / 20

5. What is the purpose of the postgres database?

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

No such database

a template for all the other database

regular database that you can use at your discretion

6 / 20

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

PGDATA

PGBASE

PGCORE

PGTIPS

7 / 20

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

True

False

8 / 20

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

choose 2

pg_temp

pg_global

pg_tablespace

pg_default

9 / 20

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

False

True

10 / 20

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

init

postman

postgres

pginit

11 / 20

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

choose 3

indexes

tables

triggers

sequences

12 / 20

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

13 / 20

13. What is a schema?

A memory area used to cache data from LRU chains

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

14 / 20

14. Postgres uses a thread based process model?

False

True

15 / 20

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

True

False

16 / 20

16. Users should not modify the template0 database

True

False

17 / 20

17. Which fork is specific for unlogged tables?

free space map

Main fork

Initialization fork

visiblilty map

18 / 20

18. TOAST tables reside in a seperate schema?

False

True

19 / 20

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

False

True

20 / 20

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

write-ahead log (WAL)

online redo logs (ORL)

rollback segments (RBS)

undo segments (UNDO)

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

Repeatable Read

Read Uncommitted

Read Committed

Serializable

2 / 10

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

False

True

3 / 10

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

Select more than 1 answer below:

Replace procedural code with declarative one.

Apply explicit locks

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

4 / 10

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

HIPPA

ACID

SOC2

SAFE

5 / 10

5. A phantom read anomaly occurs when?

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 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

6 / 10

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

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 uncommited data altered by another session

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

reading data direct from memory using pg_dirt

8 / 10

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

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

9 / 10

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

False

True

10 / 10

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

choose 3

Repeatable Read

Read Uncommitted

Read Committed

Serializable

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. status of a subtransaction is written into CLOG?

False

True

2 / 10

2. Page free space can often become fragmented?

False

True

3 / 10

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

False

True

4 / 10

4. CLOG files are stored in which directory?

PGDATA/clog

PGDATA/pg_xact

PGDATA/pg_commit

PGDATA/pg_clog

5 / 10

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

stored in PGDATA/itemptr directory

Also know as the pages table of contents

Each pointer uses 8 bytes

Each pointer uses 4 bytes

6 / 10

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

xmax

xmin

xid

xtime

7 / 10

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

False

True

8 / 10

8. index row headers like table row headers contain xmin and xmax fields?

False

True

9 / 10

9. The page header is located in the highest address?

False

True

10 / 10

10. Each page has a layer that usually consists of?

choose 2

page header

undo segment

flashback block

free space

Your score is

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