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

What is the process first launched at server start?

init

postgres

pginit

postman

2 / 20

To be able to restore data consistency, Postgres maintains

undo segments (UNDO)

online redo logs (ORL)

write-ahead log (WAL)

rollback segments (RBS)

3 / 20

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

False

True

4 / 20

What is the purpose of the public schema?

no such schema

default schema for user objects

schema used for heterogeneous replication

restricted schema for postgres internal usage only

5 / 20

Users should not modify the template0 database

False

True

6 / 20

Each tablespaces can only be assigned for use by one database

True

False

7 / 20

What is the purpose of the template0 database?

Useful for creating development schemas

No such 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

8 / 20

It is the postmasters job to listener for incoming connections?

True

False

9 / 20

To understand each other, a client and a server must use one and the same interfacing protocol?

True

False

10 / 20

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

choose 3

indexes

triggers

tables

sequences

11 / 20

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

Directory Path

Search Path

Access Path

Schema Path

12 / 20

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

PGCORE

PGBASE

PGDATA

PGTIPS

13 / 20

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

14 / 20

System Catalog tables begin with which prefix?

sys_

cat_

dba_

pg_

15 / 20

What 3 files/forks as a minimum make up a table on disk?

table map

Main fork

visiblilty map

free space map

16 / 20

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

pg_tablespace

pg_tabspace

pg_symlinks

pg_tblspc

17 / 20

What is the purpose of wal writer?

executes checkpoints

collects usage statistics for the instance.

writes WAL entries to disk

flushes dirty pages to disk.

18 / 20

TOAST tables reside in a seperate schema?

True

False

19 / 20

What is a schema?

Namespace that store all objects of a database

This is the same as a user in Postgres

A memory area used to cache data from LRU chains

The name used to refer to a super user account

20 / 20

Files are logically split into pages?

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

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

Select more than 1 answer below:

Issues a rollback after the commit to satisfy repeatable read.

Apply explicit locks

Replace procedural code with declarative one.

Use a single SQL operator

2 / 10

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

ACID

SAFE

SOC2

HIPPA

3 / 10

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 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 and commits the change.

A transaction reads one and the same row once and modifies this row and commits the change.

4 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

5 / 10

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

True

False

6 / 10

Which parameters sets the database default isolation level?

default_isolation_level

transaction_isolation_level

default_transaction_isolation

active_transaction_isolation

7 / 10

What is the default Isolation Level?

Read Uncommitted

Read Committed

Serializable

Repeatable Read

8 / 10

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

Serializable

Read Committed

Repeatable Read

Read Uncommitted

9 / 10

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

False

True

10 / 10

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.

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

The same transactions issues a commit, then a rollback to restore data to its original value

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

Information about subtransactions is stored under?

PGDATA/pg_subtrans

PGDATA/subtrans

PGDATA/pg_min

PGDATA/pg_xid

2 / 10

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

xid

xmin

xmax

xmas

3 / 10

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

False

True

4 / 10

Each page has a layer that usually consists of?

choose 2

page header

flashback block

undo segment

free space

5 / 10

UPDATE can be regarded as which 2 separate operations?

INSERT

DELETE

COMMIT

MERGE

6 / 10

Which 2 items does a Virtual XID consist of?

xmin

sequential number

backend process ID

checksum

7 / 10

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

True

False

8 / 10

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

Also know as the pages table of contents

Each pointer uses 4 bytes

Each pointer uses 8 bytes

stored in PGDATA/itemptr directory

9 / 10

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

commit log

archive log

transaction log

redo log

10 / 10

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

heap

clog

dump

view

Your score is

Cookie	Duration	Description
cookielawinfo-checkbox-analytics	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Analytics".
cookielawinfo-checkbox-functional	11 months	The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional".
cookielawinfo-checkbox-necessary	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookies is used to store the user consent for the cookies in the category "Necessary".
cookielawinfo-checkbox-others	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Other.
cookielawinfo-checkbox-performance	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Performance".
viewed_cookie_policy	11 months	The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. It does not store any personal data.