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?

writes WAL entries to disk

flushes dirty pages to disk.

executes checkpoints

collects usage statistics for the instance.

2 / 20

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

Choose 2 option

Aurora

Postgres Server

Instance

Quorum

3 / 20

3. What column in system catalogs servers as the Primary Key

obj

oid

obj#

oid#

4 / 20

4. Which 3 databases exist directly after cluster initialization?

choose 3 options

template1

postgres

sysaux

template0

5 / 20

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

StartNewPG

Initialize

CreateCluster

CreatePGC

6 / 20

6. If we create a new tablespace which directory will symbolic links be created from?

pg_tblspc

pg_tabspace

pg_symlinks

pg_tablespace

7 / 20

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

choose 3

triggers

sequences

indexes

tables

8 / 20

8. Postgres uses a thread based process model?

False

True

9 / 20

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

1MB

1GB

5GB

5MB

10 / 20

10. What is the purpose of the visibility map?

shows a page to be vacuumed or frozen

provides an audit trail for the database

provides the data decryption key

shows referential relationships for tables

11 / 20

11. The default Page size is 2k?

False

True

12 / 20

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

True

False

13 / 20

13. Users should not modify the template0 database

True

False

14 / 20

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

Schema Path

Search Path

Access Path

Directory Path

15 / 20

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

True

False

16 / 20

16. Which of below are predefined schemas?

choose 2

postgres

public

system

pg_catalog

17 / 20

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

postman

postgres

init

pginit

18 / 20

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

TOAST

BREAD

GROW

BAKE

19 / 20

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

online redo logs (ORL)

rollback segments (RBS)

write-ahead log (WAL)

undo segments (UNDO)

20 / 20

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

True

False

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 statements will start a transaction as Read Repeatable?

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

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 uncommited 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 commited data altered by another session

3 / 10

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

False

True

4 / 10

4. 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.

5 / 10

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

True

False

6 / 10

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

True

False

7 / 10

7. Which of the below are valid Isolations Levels?

choose 2

Read Committed

Serializable

Rollback Read

Random Scatter

8 / 10

8. What is the default Isolation Level?

Read Uncommitted

Serializable

Repeatable Read

Read Committed

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, 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 once and modifies this row and commits the change.

10 / 10

10. Which parameters sets the database default isolation level?

default_isolation_level

active_transaction_isolation

transaction_isolation_level

default_transaction_isolation

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

False

True

2 / 10

2. CLOG contains how many bits for each transaction?

3 / 10

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

choose 2

free space

flashback block

page header

undo segment

4 / 10

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

xid

xmax

xmin

xtime

5 / 10

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

checksum

backend process ID

xmin

sequential number

6 / 10

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

True

False

7 / 10

7. If a transaction is read only which kind of Transaction ID is it allocated?

virtual XID

magic XID

temporary XID

heap XID

8 / 10

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

False

True

9 / 10

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

stored in PGDATA/itemptr directory

Each pointer uses 8 bytes

Each pointer uses 4 bytes

Also know as the pages table of contents

10 / 10

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

True

False

Your score is

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