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

PGBASE

PGCORE

PGTIPS

PGDATA

2 / 20

It is the postmasters job to listener for incoming connections?

False

True

3 / 20

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

Sysaux Catalog

Sysasm Catalog

Sys Catalog

System Catalog

4 / 20

The information_schema schema provides information on Postgres release notes?

False

True

5 / 20

Which of below are predefined schemas?

choose 2

pg_catalog

public

system

postgres

6 / 20

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

True

False

7 / 20

What is a schema?

A memory area used to cache data from LRU chains

This is the same as a user in Postgres

Namespace that store all objects of a database

The name used to refer to a super user account

8 / 20

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

False

True

9 / 20

A schema can belong to more than one database?

False

True

10 / 20

Who is the Author of the Postgres 14 Internals book?

Egor Rogov

Dan Brown

Paul Sammy

Sam Altman

11 / 20

What is another name for the postgres process?

postmaster

masterprocess

aurora

postmanager

12 / 20

Which 3 databases exist directly after cluster initialization?

choose 3 options

sysaux

template0

template1

postgres

13 / 20

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

Choose 2 option

Aurora

Quorum

Instance

Postgres Server

14 / 20

What column in system catalogs servers as the Primary Key

obj

obj#

oid#

oid

15 / 20

Which of below are predefined schemas?

choose 3

pg_temp

pg_toast

information_schema

pg_schema

16 / 20

The default Page size is 2k?

False

True

17 / 20

Each tablespaces can only be assigned for use by one database

False

True

18 / 20

What is the process first launched at server start?

postgres

init

postman

pginit

19 / 20

What command is used to create the Postgres cluster?

Initialize

CreatePGC

CreateCluster

StartNewPG

20 / 20

Which fork keeps track of available space within pages?

wal space map

used space map

vacuum space map

free space map

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

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

False

True

2 / 10

Which of the below would best describe a dirty read?

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

reading data direct from memory using pg_dirt

3 / 10

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

Repeatable Read

Serializable

Read Uncommitted

Read Committed

4 / 10

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 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 issue a rollback.

5 / 10

A phantom read anomaly occurs when?

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

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.

6 / 10

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

Replace procedural code with declarative one.

Issues a rollback after the commit to satisfy repeatable read.

Apply explicit locks

7 / 10

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

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

CREATE EXTENSTION REPEATABLE_READ;

8 / 10

Which of the below are valid Isolations Levels?

choose 2

Read Committed

Serializable

Rollback Read

Random Scatter

9 / 10

The SQL standard specifies three isolation levels?

False

True

10 / 10

Which parameters sets the database default isolation level?

active_transaction_isolation

transaction_isolation_level

default_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

status of a subtransaction is written into CLOG?

False

True

2 / 10

Page free space can often become fragmented?

False

True

3 / 10

Indexes values also support multi versioning with several versions of an index value existing at any point in time?

False

True

4 / 10

Information about subtransactions is stored under?

PGDATA/subtrans

PGDATA/pg_xid

PGDATA/pg_subtrans

PGDATA/pg_min

5 / 10

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

True

False

6 / 10

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

pg_current_commit_id()

pg_current_xmin_id()

pg_current_xact_id()

pg_current_id()

7 / 10

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

False

True

8 / 10

CLOG contains how many bits for each transaction?

9 / 10

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

True

False

10 / 10

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

virtual XID

magic XID

temporary XID

heap XID

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.