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 uses a thread based process model?

True

False

2 / 20

It is the postmasters job to listener for incoming connections?

False

True

3 / 20

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

Choose 2 option

Instance

Postgres Server

Quorum

Aurora

4 / 20

What is the default standard size for a fork file?

1GB

5MB

1MB

5GB

5 / 20

What is the purpose of the public schema?

schema used for heterogeneous replication

default schema for user objects

restricted schema for postgres internal usage only

no such schema

6 / 20

Which of below are predefined schemas?

choose 2

system

postgres

pg_catalog

public

7 / 20

Which 3 databases exist directly after cluster initialization?

choose 3 options

sysaux

template1

template0

postgres

8 / 20

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

choose 2

pg_tablespace

pg_global

pg_default

pg_temp

9 / 20

Users should not modify the template0 database

False

True

10 / 20

What is the point of the pg_global tablespace?

stores temporary tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

stores user tables that are common to the whole cluster

stores WAL logs used for global replication

11 / 20

A schema can belong to more than one database?

False

True

12 / 20

Who is the Author of the Postgres 14 Internals book?

Egor Rogov

Sam Altman

Paul Sammy

Dan Brown

13 / 20

What column in system catalogs servers as the Primary Key

obj

oid

obj#

oid#

14 / 20

To understand each other, a client and a server must use one and the same interfacing protocol?

False

True

15 / 20

Each Database has its own System Catalog?

True

False

16 / 20

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

free space map

visiblilty map

Main fork

table map

17 / 20

Which fork is specific for unlogged tables?

visiblilty map

Initialization fork

Main fork

free space map

18 / 20

pg_catalog schema is used to store system catalog tables?

False

True

19 / 20

The default Page size is 2k?

True

False

20 / 20

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

choose 3

indexes

triggers

sequences

tables

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

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

True

False

2 / 10

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

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

3 / 10

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

choose 3

Serializable

Read Committed

Read Uncommitted

Repeatable Read

4 / 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.

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

5 / 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

6 / 10

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

False

True

7 / 10

non-repeatable read anomaly occurs when?

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 issue a rollback.

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.

8 / 10

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

True

False

9 / 10

Which parameters sets the database default isolation level?

active_transaction_isolation

default_transaction_isolation

default_isolation_level

transaction_isolation_level

10 / 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

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

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

Each pointer uses 8 bytes

stored in PGDATA/itemptr directory

Also know as the pages table of contents

Each pointer uses 4 bytes

2 / 10

UPDATE can be regarded as which 2 separate operations?

COMMIT

INSERT

MERGE

DELETE

3 / 10

status of a subtransaction is written into CLOG?

False

True

4 / 10

Page free space can often become fragmented?

False

True

5 / 10

Information about subtransactions is stored under?

PGDATA/subtrans

PGDATA/pg_min

PGDATA/pg_xid

PGDATA/pg_subtrans

6 / 10

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

True

False

7 / 10

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

False

True

8 / 10

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

False

True

9 / 10

The page header is located in the highest address?

False

True

10 / 10

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

False

True

Your score is

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