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 the purpose of wal writer?

collects usage statistics for the instance.

flushes dirty pages to disk.

writes WAL entries to disk

executes checkpoints

2 / 20

2. Which of below are predefined schemas?

choose 2

public

pg_catalog

system

postgres

3 / 20

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

False

True

4 / 20

4. What is the default standard size for a fork file?

1GB

5GB

5MB

1MB

5 / 20

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

Sysaux Catalog

System Catalog

Sys Catalog

Sysasm Catalog

6 / 20

6. What is a schema?

A memory area used to cache data from LRU chains

The name used to refer to a super user account

This is the same as a user in Postgres

Namespace that store all objects of a database

7 / 20

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

True

False

8 / 20

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

CreatePGC

CreateCluster

StartNewPG

Initialize

9 / 20

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

False

True

10 / 20

10. Postgres by default has built in connection pooling abilities?

False

True

11 / 20

11. Which 3 databases exist directly after cluster initialization?

choose 3 options

postgres

template0

template1

sysaux

12 / 20

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

Dan Brown

Paul Sammy

Egor Rogov

Sam Altman

13 / 20

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

Choose 2 option

Quorum

Aurora

Postgres Server

Instance

14 / 20

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

choose 3

triggers

indexes

tables

sequences

15 / 20

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

True

False

16 / 20

16. Which fork contains the actual table data?

Main fork

visiblilty map

table map

free space map

17 / 20

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

GROW

BAKE

TOAST

BREAD

18 / 20

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

PGTIPS

PGCORE

PGDATA

PGBASE

19 / 20

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

choose 2

pg_tablespace

pg_global

pg_default

pg_temp

20 / 20

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

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. Which of the below are valid Isolations Levels?

choose 2

Rollback Read

Serializable

Read Committed

Random Scatter

2 / 10

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

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

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

3 / 10

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

True

False

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 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

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.

6 / 10

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

SOC2

SAFE

ACID

HIPPA

7 / 10

7. The SQL standard specifies three isolation levels?

True

False

8 / 10

8. What is the default Isolation Level?

Read Committed

Serializable

Read Uncommitted

Repeatable Read

9 / 10

9. 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.

10 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

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 function can we use to find the current transaction ID?

pg_current_commit_id()

pg_current_xmin_id()

pg_current_id()

pg_current_xact_id()

2 / 10

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

False

True

3 / 10

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

True

False

4 / 10

4. CLOG files are stored in which directory?

PGDATA/pg_commit

PGDATA/pg_xact

PGDATA/pg_clog

PGDATA/clog

5 / 10

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

pagedetect

pageinspect

pageheadinfo

pagesize

6 / 10

6. If a transaction aborts, all page changes are reverted(rolled back) in place?

False

True

7 / 10

7. Page free space can often become fragmented?

True

False

8 / 10

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

xtime

xmin

xid

xmax

9 / 10

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

commit log

redo log

archive log

transaction log

10 / 10

10. Rows of TOAST tables are handled in such a way that they are never update?

True

False

Your score is

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