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. Users should not modify the template0 database

False

True

2 / 20

2. When PostgreSQL is running what can it be referred to as?

Choose 2 option

Instance

Postgres Server

Aurora

Quorum

3 / 20

3. What is the purpose of the postgres database?

regular database that you can use at your discretion

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

a template for all the other database

No such database

4 / 20

4. Which 3 databases exist directly after cluster initialization?

choose 3 options

template0

postgres

sysaux

template1

5 / 20

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

pginit

postgres

init

postman

6 / 20

6. What is the point of the pg_global tablespace?

stores user tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

stores temporary tables that are common to the whole cluster

stores WAL logs used for global replication

7 / 20

7. What is the purpose of the template0 database?

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

Useful for creating development schemas

No such database

Useful for Postgres support Services to debug issues

8 / 20

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

False

True

9 / 20

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

False

True

10 / 20

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

Egor Rogov

Dan Brown

Paul Sammy

Sam Altman

11 / 20

11. Which fork contains the actual table data?

visiblilty map

table map

Main fork

free space map

12 / 20

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

choose 3

sequences

triggers

tables

indexes

13 / 20

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

Sys Catalog

System Catalog

Sysasm Catalog

Sysaux Catalog

14 / 20

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

PGBASE

PGCORE

PGDATA

PGTIPS

15 / 20

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

True

False

16 / 20

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

False

True

17 / 20

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

False

True

18 / 20

18. What is another name for the postgres process?

aurora

masterprocess

postmaster

postmanager

19 / 20

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

pg_catalog

pg_tables

pg_system

pg_class

20 / 20

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

False

True

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. 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 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 adds some other rows satisfying this condition and commits.

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

2 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

3 / 10

3. 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 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 and commits the change.

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

4 / 10

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

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

reading data direct from memory using pg_dirt

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

5 / 10

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

False

True

6 / 10

6. Which parameters sets the database default isolation level?

default_transaction_isolation

active_transaction_isolation

transaction_isolation_level

default_isolation_level

7 / 10

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

True

False

8 / 10

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

True

False

9 / 10

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

True

False

10 / 10

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

Select more than 1 answer below:

Apply explicit locks

Issues a rollback after the commit to satisfy repeatable read.

Use a single SQL operator

Replace procedural code with declarative one.

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 is located in the highest address?

False

True

2 / 10

2. a transaction containing a savepoint is will still be considered as only a single transaction?

True

False

3 / 10

3. 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

4 / 10

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

True

False

5 / 10

5. UPDATE can be regarded as which 2 separate operations?

COMMIT

INSERT

MERGE

DELETE

6 / 10

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

False

True

7 / 10

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

True

False

8 / 10

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

COMMIT

INSERT

DELETE

CREATE

9 / 10

9. CLOG Pages are never cached in memory?

True

False

10 / 10

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

xtime

xmax

xmin

xid

Your score is

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