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

Which of below are predefined schemas?

choose 3

information_schema

pg_schema

pg_toast

pg_temp

2 / 20

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

TOAST

GROW

BAKE

BREAD

3 / 20

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

True

False

4 / 20

Which fork contains the actual table data?

free space map

visiblilty map

Main fork

table map

5 / 20

Which fork is specific for unlogged tables?

Initialization fork

free space map

Main fork

visiblilty map

6 / 20

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

choose 2

pg_global

pg_temp

pg_default

pg_tablespace

7 / 20

What is the purpose of wal writer?

flushes dirty pages to disk.

executes checkpoints

collects usage statistics for the instance.

writes WAL entries to disk

8 / 20

What is the purpose of the public schema?

schema used for heterogeneous replication

no such schema

restricted schema for postgres internal usage only

default schema for user objects

9 / 20

Postgres uses a thread based process model?

False

True

10 / 20

Each Database has its own System Catalog?

True

False

11 / 20

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

Choose 2 option

Quorum

Postgres Server

Aurora

Instance

12 / 20

What is the process first launched at server start?

postman

postgres

pginit

init

13 / 20

Who is the Author of the Postgres 14 Internals book?

Paul Sammy

Dan Brown

Sam Altman

Egor Rogov

14 / 20

What is the purpose of the postgres database?

a template for all the other database

No such database

regular database that you can use at your discretion

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

15 / 20

Which fork keeps track of available space within pages?

free space map

wal space map

used space map

vacuum space map

16 / 20

How many files or forks on disk will a 10Mb table with no index have?

17 / 20

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

free space map

table map

visiblilty map

Main fork

18 / 20

What column in system catalogs servers as the Primary Key

obj#

oid#

oid

obj

19 / 20

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

True

False

20 / 20

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

Search Path

Schema Path

Access Path

Directory Path

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

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

Serializable

Repeatable Read

Read Uncommitted

Read Committed

2 / 10

Which parameters sets the database default isolation level?

active_transaction_isolation

transaction_isolation_level

default_isolation_level

default_transaction_isolation

3 / 10

Which of the below would best describe a dirty read?

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

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

reading data direct from memory using pg_dirt

reading the data directly from file using a text editor such as vi or notepad

4 / 10

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

False

True

5 / 10

A phantom read anomaly occurs when?

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 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

6 / 10

The SQL standard specifies three isolation levels?

True

False

7 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

8 / 10

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

ACID

HIPPA

SOC2

SAFE

9 / 10

Data Consistency is best handled at the application layer rather than at the database layer?

False

True

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

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

heap

dump

clog

view

2 / 10

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

pg_current_id()

pg_current_xmin_id()

pg_current_commit_id()

pg_current_xact_id()

3 / 10

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

False

True

4 / 10

Information about subtransactions is stored under?

PGDATA/pg_min

PGDATA/pg_xid

PGDATA/subtrans

PGDATA/pg_subtrans

5 / 10

What does an Item Pointer contain?

choose 3

tuple offset from the start of the page

tuple status

tuple length

tuple xid

6 / 10

CLOG files are stored in which directory?

PGDATA/pg_xact

PGDATA/clog

PGDATA/pg_commit

PGDATA/pg_clog

7 / 10

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

False

True

8 / 10

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

False

True

9 / 10

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

xmin

xtime

xid

xmax

10 / 10

UPDATE can be regarded as which 2 separate operations?

DELETE

COMMIT

INSERT

MERGE

Your score is

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