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

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

pg_tblspc

pg_tablespace

pg_tabspace

pg_symlinks

2 / 20

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

3 / 20

Which 3 databases exist directly after cluster initialization?

choose 3 options

postgres

sysaux

template1

template0

4 / 20

A single Postgres Instance can server only one database?

False

True

5 / 20

Which of below are predefined schemas?

choose 3

pg_temp

pg_schema

information_schema

pg_toast

6 / 20

What is the purpose of the visibility map?

provides an audit trail for the database

provides the data decryption key

shows referential relationships for tables

shows a page to be vacuumed or frozen

7 / 20

Postgres server spawns a new backend session for each connection?

True

False

8 / 20

What is the default standard size for a fork file?

1MB

5MB

1GB

5GB

9 / 20

What is another name for the postgres process?

aurora

masterprocess

postmaster

postmanager

10 / 20

Postgres by default has built in connection pooling abilities?

True

False

11 / 20

Who is the Author of the Postgres 14 Internals book?

Paul Sammy

Dan Brown

Egor Rogov

Sam Altman

12 / 20

What is the purpose of the template1 database?

a template for all the other databases

database used for temporary tables

No such database

regular database that you can use at your discretion

13 / 20

What is the process first launched at server start?

postman

pginit

init

postgres

14 / 20

Some System Catalog tables are common to all databases in the cluster?

True

False

15 / 20

What is the name of the catalog that stores metadata for all cluster objects?

System Catalog

Sysaux Catalog

Sys Catalog

Sysasm Catalog

16 / 20

Each tablespaces can only be assigned for use by one database

True

False

17 / 20

What command is used to create the Postgres cluster?

StartNewPG

CreatePGC

CreateCluster

Initialize

18 / 20

To be able to restore data consistency, Postgres maintains

write-ahead log (WAL)

online redo logs (ORL)

rollback segments (RBS)

undo segments (UNDO)

19 / 20

Which of below are predefined schemas?

choose 2

pg_catalog

system

public

postgres

20 / 20

What is the purpose of autovacuum?

Rebuilds indexes with b level greater than 2

Deletes old logs and traces on disk

Performs a backup of WAL logs

Removes stale data from tables and indexes

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

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

3 / 10

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

True

False

4 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

5 / 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 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.

A transaction reads one and the same row once and modifies this row and commits the change.

6 / 10

Which of the below would best describe a dirty read?

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

reading data direct from memory using pg_dirt

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

7 / 10

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

True

False

8 / 10

The SQL standard specifies three isolation levels?

True

False

9 / 10

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

HIPPA

SOC2

SAFE

ACID

10 / 10

Which parameters sets the database default isolation level?

default_transaction_isolation

default_isolation_level

active_transaction_isolation

transaction_isolation_level

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

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

False

True

2 / 10

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

True

False

3 / 10

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

True

False

4 / 10

If a transaction aborts, all page changes are reverted(rolled back) in place?

True

False

5 / 10

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

False

True

6 / 10

Which 2 items does a Virtual XID consist of?

xmin

sequential number

checksum

backend process ID

7 / 10

Which of the below are true about a Pages Item Pointer?

Each pointer uses 4 bytes

Each pointer uses 8 bytes

stored in PGDATA/itemptr directory

Also know as the pages table of contents

8 / 10

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

view

clog

dump

heap

9 / 10

When a row is created, its xmin value is set to the transaction ID of which command?

CREATE

COMMIT

INSERT

DELETE

10 / 10

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

pagedetect

pageinspect

pagesize

pageheadinfo

Your score is

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