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

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

True

False

2 / 20

Which of below are predefined schemas?

choose 2

postgres

public

pg_catalog

system

3 / 20

pg_catalog schema is used to store system catalog tables?

False

True

4 / 20

Tablespaces are used to define physical data layout?

False

True

5 / 20

What is the purpose of the template0 database?

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

No such database

Useful for creating development schemas

Useful for Postgres support Services to debug issues

6 / 20

Which fork contains the actual table data?

Main fork

table map

visiblilty map

free space map

7 / 20

It is the postmasters job to listener for incoming connections?

False

True

8 / 20

Each tablespaces can only be assigned for use by one database

False

True

9 / 20

What is the purpose of the postgres database?

a template for all the other database

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

regular database that you can use at your discretion

No such database

10 / 20

The default Page size is 2k?

False

True

11 / 20

Which fork keeps track of available space within pages?

free space map

vacuum space map

used space map

wal space map

12 / 20

TOAST tables reside in a seperate schema?

False

True

13 / 20

A single Postgres Instance can server only one database?

True

False

14 / 20

Each Database has its own System Catalog?

False

True

15 / 20

Files are logically split into pages?

True

False

16 / 20

Which 3 databases exist directly after cluster initialization?

choose 3 options

template1

template0

sysaux

postgres

17 / 20

A Postgres cluster consists of 2 or more physical servers accessing one Postgres Instance?

False

True

18 / 20

To be able to restore data consistency, Postgres maintains

rollback segments (RBS)

undo segments (UNDO)

write-ahead log (WAL)

online redo logs (ORL)

19 / 20

What is a schema?

This is the same as a user in Postgres

The name used to refer to a super user account

Namespace that store all objects of a database

A memory area used to cache data from LRU chains

20 / 20

Postgres server spawns a new backend session for each connection?

False

True

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

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

True

False

2 / 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

Use a single SQL operator

Replace procedural code with declarative one.

3 / 10

What is the default Isolation Level?

Read Uncommitted

Serializable

Repeatable Read

Read Committed

4 / 10

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

choose 3

Serializable

Read Committed

Repeatable Read

Read Uncommitted

5 / 10

The SQL standard specifies three isolation levels?

True

False

6 / 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 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.

A transaction reads one and the same row twice, another transaction modifies this row between these reads and commits the change.

7 / 10

Which parameters sets the database default isolation level?

transaction_isolation_level

default_transaction_isolation

default_isolation_level

active_transaction_isolation

8 / 10

Which of the below would best describe a dirty read?

a session being able to see uncommited 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

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

9 / 10

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

False

True

10 / 10

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

Read Uncommitted

Serializable

Read Committed

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

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

False

True

2 / 10

A page along with its tuples is read into the buffer cache with compression transformations to enhance cache efficiency?

True

False

3 / 10

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

False

True

4 / 10

The page header is located in the highest address?

False

True

5 / 10

Page header sizes can be easily displayed using the <choose from answers> extension

pageheadinfo

pagesize

pagedetect

pageinspect

6 / 10

Information about subtransactions is stored under?

PGDATA/subtrans

PGDATA/pg_subtrans

PGDATA/pg_min

PGDATA/pg_xid

7 / 10

Which 2 items does a Virtual XID consist of?

sequential number

xmin

backend process ID

checksum

8 / 10

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

True

False

9 / 10

What does an Item Pointer contain?

choose 3

tuple length

tuple offset from the start of the page

tuple xid

tuple status

10 / 10

psql provides a special mode that allows you to continue a transaction after a failure?

True

False

Your score is

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