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

System Catalog tables begin with which prefix?

dba_

pg_

sys_

cat_

2 / 20

It is the postmasters job to listener for incoming connections?

False

True

3 / 20

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

table map

free space map

Main fork

visiblilty map

4 / 20

What is the purpose of the template1 database?

No such database

regular database that you can use at your discretion

database used for temporary tables

a template for all the other databases

5 / 20

What is the purpose of the visibility map?

provides an audit trail for the database

provides the data decryption key

shows a page to be vacuumed or frozen

shows referential relationships for tables

6 / 20

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

pg_symlinks

pg_tabspace

pg_tblspc

pg_tablespace

7 / 20

What is the purpose of the template0 database?

Useful for creating development schemas

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

8 / 20

Each Database has its own System Catalog?

True

False

9 / 20

What is the process first launched at server start?

postman

postgres

pginit

init

10 / 20

Who is the Author of the Postgres 14 Internals book?

Sam Altman

Dan Brown

Paul Sammy

Egor Rogov

11 / 20

What is another name for the postgres process?

postmanager

postmaster

aurora

masterprocess

12 / 20

TOAST tables reside in a seperate schema?

True

False

13 / 20

Which of below are predefined schemas?

choose 3

pg_toast

pg_schema

information_schema

pg_temp

14 / 20

Which fork is specific for unlogged tables?

visiblilty map

Initialization fork

free space map

Main fork

15 / 20

Postgres uses a thread based process model?

True

False

16 / 20

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

17 / 20

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

choose 2

pg_global

pg_temp

pg_default

pg_tablespace

18 / 20

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

pg_tables

pg_class

pg_system

pg_catalog

19 / 20

What is the purpose of the postgres database?

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

a template for all the other database

regular database that you can use at your discretion

No such database

20 / 20

What is the purpose of wal writer?

writes WAL entries to disk

executes checkpoints

collects usage statistics for the instance.

flushes dirty pages to disk.

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

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

2 / 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 commited data altered by another session

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

3 / 10

What is the default Isolation Level?

Read Uncommitted

Read Committed

Serializable

Repeatable Read

4 / 10

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

False

True

5 / 10

Which of the below are valid Isolations Levels?

choose 2

Serializable

Rollback Read

Random Scatter

Read Committed

6 / 10

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

Read Committed

Repeatable Read

Serializable

Read Uncommitted

7 / 10

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

False

True

8 / 10

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

False

True

9 / 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 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.

10 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION 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

Rows of TOAST tables are handled in such a way that they are never update?

True

False

2 / 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

stored in PGDATA/itemptr directory

Each pointer uses 8 bytes

3 / 10

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

transaction log

redo log

commit log

archive log

4 / 10

status of a subtransaction is written into CLOG?

True

False

5 / 10

CLOG Pages are never cached in memory?

False

True

6 / 10

UPDATE can be regarded as which 2 separate operations?

COMMIT

MERGE

DELETE

INSERT

7 / 10

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

False

True

8 / 10

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

clog

view

heap

dump

9 / 10

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

xmin

xid

xmax

xmas

10 / 10

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

False

True

Your score is

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