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. Postgres uses a thread based process model?

False

True

2 / 20

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

CreatePGC

Initialize

StartNewPG

CreateCluster

3 / 20

3. Which fork keeps track of available space within pages?

free space map

used space map

vacuum space map

wal space map

4 / 20

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

5 / 20

5. Which 3 databases exist directly after cluster initialization?

choose 3 options

template1

postgres

template0

sysaux

6 / 20

6. Users should not modify the template0 database

False

True

7 / 20

7. 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

regular database that you can use at your discretion

a template for all the other database

8 / 20

8. Each Database has its own System Catalog?

False

True

9 / 20

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

pg_tblspc

pg_tablespace

pg_tabspace

pg_symlinks

10 / 20

10. Which fork contains the actual table data?

table map

visiblilty map

Main fork

free space map

11 / 20

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

False

True

12 / 20

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

False

True

13 / 20

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

Sysasm Catalog

Sys Catalog

System Catalog

Sysaux Catalog

14 / 20

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

init

postgres

postman

pginit

15 / 20

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

pg_catalog

pg_class

pg_system

pg_tables

16 / 20

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

choose 3

tables

sequences

triggers

indexes

17 / 20

17. What is the purpose of the template1 database?

database used for temporary tables

No such database

a template for all the other databases

regular database that you can use at your discretion

18 / 20

18. A single Postgres Instance can server only one database?

True

False

19 / 20

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

True

False

20 / 20

20. What is the point of the pg_global tablespace?

stores user tables that are common to the whole cluster

stores WAL logs used for global replication

stores system catalog objects that are common to the whole cluster

stores temporary tables that are common to the whole cluster

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 of the below are valid Isolations Levels?

choose 2

Read Committed

Rollback Read

Serializable

Random Scatter

3 / 10

3. What is the default Isolation Level?

Read Committed

Repeatable Read

Serializable

Read Uncommitted

4 / 10

4. Which parameters sets the database default isolation level?

transaction_isolation_level

default_transaction_isolation

default_isolation_level

active_transaction_isolation

5 / 10

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

False

True

6 / 10

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

choose 3

Read Uncommitted

Serializable

Read Committed

Repeatable Read

7 / 10

7. 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 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

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

8 / 10

8. 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 commited data altered by another session

reading data direct from memory using pg_dirt

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

9 / 10

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

False

True

10 / 10

10. 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 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.

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?

True

False

2 / 10

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

False

True

3 / 10

3. What does an Item Pointer contain?

choose 3

tuple length

tuple status

tuple xid

tuple offset from the start of the page

4 / 10

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

xmin

checksum

sequential number

backend process ID

5 / 10

5. status of a subtransaction is written into CLOG?

True

False

6 / 10

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

True

False

7 / 10

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

True

False

8 / 10

8. To identify different versions of one and the same row, PostgreSQL marks each of them with which two value?

xmax

xid

xmin

xmas

9 / 10

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

choose 2

page header

undo segment

free space

flashback block

10 / 10

10. Which function can we use to find the current transaction ID?

pg_current_xact_id()

pg_current_xmin_id()

pg_current_commit_id()

pg_current_id()

Your score is

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