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 the template0 database?

Useful for Postgres support Services to debug issues

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

No such database

Useful for creating development schemas

2 / 20

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

False

True

3 / 20

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

True

False

4 / 20

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

5 / 20

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

choose 3

indexes

sequences

triggers

tables

6 / 20

6. Tablespaces are used to define physical data layout?

True

False

7 / 20

7. Which 3 databases exist directly after cluster initialization?

choose 3 options

postgres

sysaux

template0

template1

8 / 20

8. Which fork is specific for unlogged tables?

Main fork

Initialization fork

free space map

visiblilty map

9 / 20

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

False

True

10 / 20

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

False

True

11 / 20

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

pg_tblspc

pg_tablespace

pg_symlinks

pg_tabspace

12 / 20

12. What is the point of the pg_global tablespace?

stores user tables that are common to the whole cluster

stores temporary tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

stores WAL logs used for global replication

13 / 20

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

choose 2

pg_tablespace

pg_default

pg_temp

pg_global

14 / 20

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

postman

init

postgres

pginit

15 / 20

15. Which of below are predefined schemas?

choose 3

pg_toast

information_schema

pg_schema

pg_temp

16 / 20

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

True

False

17 / 20

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

used space map

vacuum space map

free space map

wal space map

18 / 20

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

True

False

19 / 20

19. What is the purpose of the postgres database?

a template for all the other database

regular database that you can use at your discretion

No such database

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

20 / 20

20. Postgres uses a thread based process model?

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. What is the default Isolation Level?

Read Uncommitted

Repeatable Read

Serializable

Read Committed

2 / 10

2. non-repeatable read anomaly occurs when?

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.

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.

3 / 10

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

Read Committed

Read Uncommitted

Serializable

Repeatable Read

4 / 10

4. 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 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.

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

5 / 10

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

SAFE

HIPPA

SOC2

ACID

6 / 10

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

choose 3

Read Uncommitted

Repeatable Read

Read Committed

Serializable

7 / 10

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

False

True

8 / 10

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

False

True

9 / 10

9. Which parameters sets the database default isolation level?

default_transaction_isolation

transaction_isolation_level

active_transaction_isolation

default_isolation_level

10 / 10

10. 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;

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. status of a subtransaction is written into CLOG?

False

True

2 / 10

2. In Postgres, tables are often referred to as which of the below?

clog

view

dump

heap

3 / 10

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

stored in PGDATA/itemptr directory

Each pointer uses 4 bytes

Each pointer uses 8 bytes

Also know as the pages table of contents

4 / 10

4. CLOG files are stored in which directory?

PGDATA/clog

PGDATA/pg_clog

PGDATA/pg_xact

PGDATA/pg_commit

5 / 10

5. Page free space can often become fragmented?

False

True

6 / 10

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

False

True

7 / 10

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

False

True

8 / 10

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

heap XID

virtual XID

temporary XID

magic XID

9 / 10

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

commit log

redo log

transaction log

archive log

10 / 10

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

False

True

Your score is

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