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 a schema?

This is the same as a user in Postgres

The name used to refer to a super user account

A memory area used to cache data from LRU chains

Namespace that store all objects of a database

2 / 20

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

False

True

3 / 20

3. Which fork contains the actual table data?

table map

visiblilty map

free space map

Main fork

4 / 20

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

TOAST

BAKE

BREAD

GROW

5 / 20

5. What is the point of the pg_global tablespace?

stores WAL logs used for global replication

stores temporary tables that are common to the whole cluster

stores user tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

6 / 20

6. Which of below are predefined schemas?

choose 3

information_schema

pg_toast

pg_temp

pg_schema

7 / 20

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

StartNewPG

CreatePGC

Initialize

CreateCluster

8 / 20

8. What is the purpose of the postgres database?

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

a template for all the other database

No such database

regular database that you can use at your discretion

9 / 20

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

choose 2

pg_temp

pg_global

pg_tablespace

pg_default

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

template0

template1

sysaux

postgres

12 / 20

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

Egor Rogov

Dan Brown

Paul Sammy

Sam Altman

13 / 20

13. Tablespaces are used to define physical data layout?

False

True

14 / 20

14. What is the purpose of wal writer?

executes checkpoints

flushes dirty pages to disk.

collects usage statistics for the instance.

writes WAL entries to disk

15 / 20

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

choose 3

triggers

tables

sequences

indexes

16 / 20

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

False

True

17 / 20

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

True

False

18 / 20

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

PGDATA

PGCORE

PGTIPS

PGBASE

19 / 20

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

pg_system

pg_catalog

pg_class

pg_tables

20 / 20

20. Which fork is specific for unlogged tables?

visiblilty map

free space map

Initialization fork

Main fork

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

True

False

2 / 10

2. Which parameters sets the database default isolation level?

active_transaction_isolation

transaction_isolation_level

default_transaction_isolation

default_isolation_level

3 / 10

3. Which of the below are valid Isolations Levels?

choose 2

Read Committed

Serializable

Rollback Read

Random Scatter

4 / 10

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

True

False

5 / 10

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

Serializable

Read Uncommitted

Read Committed

Repeatable Read

6 / 10

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

Select more than 1 answer below:

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

Apply explicit locks

Replace procedural code with declarative one.

7 / 10

7. What is the default Isolation Level?

Read Committed

Repeatable Read

Read Uncommitted

Serializable

8 / 10

8. 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.

9 / 10

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

HIPPA

SAFE

SOC2

ACID

10 / 10

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

False

True

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. CLOG files are stored in which directory?

PGDATA/pg_xact

PGDATA/clog

PGDATA/pg_clog

PGDATA/pg_commit

2 / 10

2. CLOG contains how many bits for each transaction?

3 / 10

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

False

True

4 / 10

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

choose 2

free space

page header

undo segment

flashback block

5 / 10

5. What does an Item Pointer contain?

choose 3

tuple length

tuple status

tuple xid

tuple offset from the start of the page

6 / 10

6. CLOG Pages are never cached in memory?

False

True

7 / 10

7. at any one time Postgres can have several versions of a row?

False

True

8 / 10

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

xmin

sequential number

checksum

backend process ID

9 / 10

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

stored in PGDATA/itemptr directory

Each pointer uses 8 bytes

Also know as the pages table of contents

Each pointer uses 4 bytes

10 / 10

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

CREATE

DELETE

COMMIT

INSERT

Your score is

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