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

Postgres server spawns a new backend session for each connection?

True

False

2 / 20

Each tablespaces can only be assigned for use by one database

True

False

3 / 20

What command is used to create the Postgres cluster?

Initialize

StartNewPG

CreatePGC

CreateCluster

4 / 20

A single Postgres Instance can server only one database?

False

True

5 / 20

The information_schema schema provides information on Postgres release notes?

True

False

6 / 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

7 / 20

What column in system catalogs servers as the Primary Key

obj

oid#

oid

obj#

8 / 20

A schema can belong to more than one database?

True

False

9 / 20

When PostgreSQL is running what can it be referred to as?

Choose 2 option

Quorum

Postgres Server

Aurora

Instance

10 / 20

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

GROW

BREAD

BAKE

TOAST

11 / 20

What is the purpose of wal writer?

executes checkpoints

writes WAL entries to disk

collects usage statistics for the instance.

flushes dirty pages to disk.

12 / 20

Which of the below objects can be referred to as relations?

choose 3

indexes

tables

sequences

triggers

13 / 20

Tablespaces can be used to segregate data based on performance needs?

False

True

14 / 20

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

False

True

15 / 20

What is a schema?

Namespace that store all objects of a database

A memory area used to cache data from LRU chains

The name used to refer to a super user account

This is the same as a user in Postgres

16 / 20

Who is the Author of the Postgres 14 Internals book?

Sam Altman

Egor Rogov

Paul Sammy

Dan Brown

17 / 20

What is the purpose of the template0 database?

No such 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

18 / 20

Which fork is specific for unlogged tables?

Main fork

visiblilty map

free space map

Initialization fork

19 / 20

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

choose 2

pg_tablespace

pg_temp

pg_default

pg_global

20 / 20

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

True

False

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?

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

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.

2 / 10

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

True

False

3 / 10

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

False

True

4 / 10

What is the default Isolation Level?

Read Committed

Serializable

Read Uncommitted

Repeatable Read

5 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

6 / 10

Which of the below are valid Isolations Levels?

choose 2

Read Committed

Rollback Read

Random Scatter

Serializable

7 / 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

8 / 10

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

choose 3

Read Uncommitted

Serializable

Repeatable Read

Read Committed

9 / 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.

Replace procedural code with declarative one.

Apply explicit locks

Use a single SQL operator

10 / 10

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

False

True

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

status of a subtransaction is written into CLOG?

False

True

2 / 10

index row headers like table row headers contain xmin and xmax fields?

True

False

3 / 10

CLOG contains how many bits for each transaction?

4 / 10

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

False

True

5 / 10

Page free space can often become fragmented?

True

False

6 / 10

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

DELETE

COMMIT

INSERT

CREATE

7 / 10

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

True

False

8 / 10

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

True

False

9 / 10

Postgres table physical data files are always cross compatible across platforms?

False

True

10 / 10

What does an Item Pointer contain?

choose 3

tuple status

tuple xid

tuple offset from the start of the page

tuple length

Your score is

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