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 fork is specific for unlogged tables?

Main fork

Initialization fork

free space map

visiblilty map

2 / 20

Users should not modify the template0 database

False

True

3 / 20

System Catalog tables begin with which prefix?

sys_

cat_

pg_

dba_

4 / 20

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

5 / 20

Which fork contains the actual table data?

table map

visiblilty map

free space map

Main fork

6 / 20

What is the purpose of the visibility map?

shows a page to be vacuumed or frozen

shows referential relationships for tables

provides the data decryption key

provides an audit trail for the database

7 / 20

It is the postmasters job to listener for incoming connections?

False

True

8 / 20

What is another name for the postgres process?

masterprocess

aurora

postmaster

postmanager

9 / 20

A single Postgres Instance can server only one database?

True

False

10 / 20

What is the purpose of autovacuum?

Deletes old logs and traces on disk

Rebuilds indexes with b level greater than 2

Removes stale data from tables and indexes

Performs a backup of WAL logs

11 / 20

What is the point of the pg_global tablespace?

stores user 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

stores temporary tables that are common to the whole cluster

12 / 20

What command is used to create the Postgres cluster?

CreateCluster

Initialize

CreatePGC

StartNewPG

13 / 20

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

True

False

14 / 20

Which of below are predefined schemas?

choose 2

system

pg_catalog

postgres

public

15 / 20

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

choose 2

pg_default

pg_global

pg_tablespace

pg_temp

16 / 20

What is the default standard size for a fork file?

5MB

1MB

5GB

1GB

17 / 20

TOAST tables reside in a seperate schema?

False

True

18 / 20

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

pg_system

pg_catalog

pg_tables

pg_class

19 / 20

Who is the Author of the Postgres 14 Internals book?

Egor Rogov

Sam Altman

Paul Sammy

Dan Brown

20 / 20

Which fork keeps track of available space within pages?

wal space map

vacuum space map

free space map

used 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

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

Repeatable Read

Read Committed

Serializable

Read Uncommitted

2 / 10

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

True

False

3 / 10

Which of the below would best describe a dirty read?

reading data direct from memory using pg_dirt

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

4 / 10

non-repeatable read anomaly occurs when?

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 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

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

SAFE

SOC2

HIPPA

ACID

6 / 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 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.

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

7 / 10

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

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

8 / 10

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

choose 3

Read Uncommitted

Serializable

Read Committed

Repeatable Read

9 / 10

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

True

False

10 / 10

Which of the below are valid Isolations Levels?

choose 2

Read Committed

Rollback Read

Random Scatter

Serializable

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

CLOG files are stored in which directory?

PGDATA/pg_clog

PGDATA/pg_xact

PGDATA/pg_commit

PGDATA/clog

2 / 10

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

3 / 10

CLOG contains how many bits for each transaction?

4 / 10

virtual IDs exist only in PGDATA/pg_vxid when not cached?

True

False

5 / 10

indexes do not use row versioning?

False

True

6 / 10

Information about subtransactions is stored under?

PGDATA/pg_subtrans

PGDATA/subtrans

PGDATA/pg_min

PGDATA/pg_xid

7 / 10

Page free space can often become fragmented?

True

False

8 / 10

status of a subtransaction is written into CLOG?

False

True

9 / 10

Each page has a layer that usually consists of?

choose 2

free space

undo segment

page header

flashback block

10 / 10

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

clog

dump

view

heap

Your score is

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