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

Which of below are predefined schemas?

choose 3

information_schema

pg_toast

pg_temp

pg_schema

2 / 20

TOAST tables reside in a seperate schema?

False

True

3 / 20

What column in system catalogs servers as the Primary Key

oid

oid#

obj

obj#

4 / 20

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

BAKE

GROW

BREAD

TOAST

5 / 20

Which fork keeps track of available space within pages?

free space map

vacuum space map

used space map

wal space map

6 / 20

The information_schema schema provides information on Postgres release notes?

True

False

7 / 20

Postgres uses a thread based process model?

True

False

8 / 20

pg_catalog schema is used to store system catalog tables?

True

False

9 / 20

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

False

True

10 / 20

Postgres by default has built in connection pooling abilities?

False

True

11 / 20

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

12 / 20

What is another name for the postgres process?

aurora

masterprocess

postmanager

postmaster

13 / 20

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

Sys Catalog

Sysasm Catalog

Sysaux Catalog

System Catalog

14 / 20

A single Postgres Instance can server only one database?

True

False

15 / 20

What is the purpose of the template1 database?

database used for temporary tables

No such database

regular database that you can use at your discretion

a template for all the other databases

16 / 20

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

pg_tables

pg_catalog

pg_class

pg_system

17 / 20

What 3 files/forks as a minimum make up a table on disk?

free space map

table map

Main fork

visiblilty map

18 / 20

What is the purpose of the postgres database?

No such database

regular database that you can use at your discretion

a template for all the other database

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

19 / 20

Postgres server spawns a new backend session for each connection?

True

False

20 / 20

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

choose 2

pg_temp

pg_global

pg_tablespace

pg_default

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 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.

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

2 / 10

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

Select more than 1 answer below:

Use a single SQL operator

Replace procedural code with declarative one.

Apply explicit locks

Issues a rollback after the commit to satisfy repeatable read.

3 / 10

A phantom read anomaly occurs when?

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 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.

A transactions inserts a null value into a not null columns and commits

4 / 10

Which of the below would best describe a dirty read?

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

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

reading data direct from memory using pg_dirt

5 / 10

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

False

True

6 / 10

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

Read Uncommitted

Repeatable Read

Read Committed

Serializable

7 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION 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

HIPPA

SOC2

SAFE

10 / 10

Which parameters sets the database default isolation level?

active_transaction_isolation

default_isolation_level

transaction_isolation_level

default_transaction_isolation

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

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

True

False

2 / 10

Which 2 items does a Virtual XID consist of?

xmin

backend process ID

sequential number

checksum

3 / 10

Each page has a layer that usually consists of?

choose 2

free space

undo segment

page header

flashback block

4 / 10

status of a subtransaction is written into CLOG?

True

False

5 / 10

indexes do not use row versioning?

False

True

6 / 10

To identify different versions of one and the same row, PostgreSQL marks each of them with which two value?

xmax

xmas

xmin

xid

7 / 10

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

True

False

8 / 10

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

INSERT

CREATE

COMMIT

DELETE

9 / 10

Page free space can often become fragmented?

False

True

10 / 10

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

heap

clog

view

dump

Your score is

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