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

It is the postmasters job to listener for incoming connections?

True

False

2 / 20

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

False

True

3 / 20

What is the purpose of autovacuum?

Rebuilds indexes with b level greater than 2

Deletes old logs and traces on disk

Removes stale data from tables and indexes

Performs a backup of WAL logs

4 / 20

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

PGDATA

PGTIPS

PGCORE

PGBASE

5 / 20

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

6 / 20

What is another name for the postgres process?

masterprocess

aurora

postmaster

postmanager

7 / 20

Which of below are predefined schemas?

choose 3

pg_toast

pg_schema

information_schema

pg_temp

8 / 20

Which 3 databases exist directly after cluster initialization?

choose 3 options

template0

postgres

sysaux

template1

9 / 20

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

BREAD

GROW

TOAST

BAKE

10 / 20

What is the purpose of the template0 database?

Useful for Postgres support Services to debug issues

No such database

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

Useful for creating development schemas

11 / 20

Which fork contains the actual table data?

visiblilty map

free space map

Main fork

table map

12 / 20

What command is used to create the Postgres cluster?

StartNewPG

CreateCluster

Initialize

CreatePGC

13 / 20

Who is the Author of the Postgres 14 Internals book?

Paul Sammy

Dan Brown

Sam Altman

Egor Rogov

14 / 20

The information_schema schema provides information on Postgres release notes?

False

True

15 / 20

A schema can belong to more than one database?

True

False

16 / 20

To be able to restore data consistency, Postgres maintains

undo segments (UNDO)

online redo logs (ORL)

rollback segments (RBS)

write-ahead log (WAL)

17 / 20

The default Page size is 2k?

True

False

18 / 20

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

pg_tables

pg_class

pg_system

pg_catalog

19 / 20

Postgres server spawns a new backend session for each connection?

True

False

20 / 20

System Catalog tables begin with which prefix?

dba_

sys_

pg_

cat_

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

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 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.

2 / 10

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

True

False

3 / 10

Which parameters sets the database default isolation level?

default_isolation_level

default_transaction_isolation

active_transaction_isolation

transaction_isolation_level

4 / 10

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

Read Committed

Repeatable Read

Read Uncommitted

Serializable

5 / 10

The SQL standard specifies three isolation levels?

False

True

6 / 10

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

HIPPA

SOC2

SAFE

ACID

7 / 10

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

choose 3

Repeatable Read

Read Uncommitted

Read Committed

Serializable

8 / 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 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.

The same transactions issues a commit, then a rollback to restore data to its original value

9 / 10

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

True

False

10 / 10

What is the default Isolation Level?

Serializable

Repeatable Read

Read Uncommitted

Read Committed

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

view

dump

clog

2 / 10

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

True

False

3 / 10

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

True

False

4 / 10

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

False

True

5 / 10

Which 2 items does a Virtual XID consist of?

sequential number

xmin

backend process ID

checksum

6 / 10

a transaction containing a savepoint is will still be considered as only a single transaction?

False

True

7 / 10

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

False

True

8 / 10

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

temporary XID

heap XID

magic XID

virtual XID

9 / 10

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

True

False

10 / 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

Your score is

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