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

Each tablespaces can only be assigned for use by one database

True

False

2 / 20

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

False

True

3 / 20

What is the point of the pg_global tablespace?

stores WAL logs used for global replication

stores system catalog objects that are common to the whole cluster

stores user tables that are common to the whole cluster

stores temporary tables that are common to the whole cluster

4 / 20

What is the purpose of the template1 database?

regular database that you can use at your discretion

No such database

a template for all the other databases

database used for temporary tables

5 / 20

Which fork keeps track of available space within pages?

used space map

free space map

wal space map

vacuum space map

6 / 20

A single Postgres Instance can server only one database?

True

False

7 / 20

pg_catalog schema is used to store system catalog tables?

False

True

8 / 20

How does Postgres know which schema to use if not specified?

Search Path

Schema Path

Directory Path

Access Path

9 / 20

Postgres by default has built in connection pooling abilities?

False

True

10 / 20

What is the purpose of wal writer?

writes WAL entries to disk

collects usage statistics for the instance.

executes checkpoints

flushes dirty pages to disk.

11 / 20

Postgres server spawns a new backend session for each connection?

False

True

12 / 20

What is a schema?

This is the same as a user in Postgres

Namespace that store all objects of a database

The name used to refer to a super user account

A memory area used to cache data from LRU chains

13 / 20

What is the purpose of the postgres database?

No such database

a template for all the other database

regular database that you can use at your discretion

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

14 / 20

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

False

True

15 / 20

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

pg_symlinks

pg_tblspc

pg_tablespace

pg_tabspace

16 / 20

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

False

True

17 / 20

Which of below are predefined schemas?

choose 3

pg_toast

pg_temp

information_schema

pg_schema

18 / 20

Which of below are predefined schemas?

choose 2

pg_catalog

public

system

postgres

19 / 20

Each Database has its own System Catalog?

True

False

20 / 20

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

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

Which of the below would best describe a dirty read?

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

reading the data directly from file using a text editor such as vi or notepad

2 / 10

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

False

True

3 / 10

What are some of database features we can use to avoid a non repeatable read?

Select more than 1 answer below:

Apply explicit locks

Replace procedural code with declarative one.

Issues a rollback after the commit to satisfy repeatable read.

Use a single SQL operator

4 / 10

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

False

True

5 / 10

Which parameters sets the database default isolation level?

active_transaction_isolation

default_transaction_isolation

default_isolation_level

transaction_isolation_level

6 / 10

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

False

True

7 / 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;

8 / 10

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

False

True

9 / 10

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

ACID

SAFE

HIPPA

SOC2

10 / 10

A phantom read anomaly occurs when?

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

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.

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

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

True

False

2 / 10

indexes do not use row versioning?

False

True

3 / 10

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

False

True

4 / 10

Tuples can also be referred to as columns?

True

False

5 / 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

6 / 10

The page header is located in the highest address?

True

False

7 / 10

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

True

False

8 / 10

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

True

False

9 / 10

CLOG contains how many bits for each transaction?

10 / 10

Page free space can often become fragmented?

True

False

Your score is

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