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

System Catalog tables begin with which prefix?

cat_

pg_

dba_

sys_

2 / 20

Who is the Author of the Postgres 14 Internals book?

Egor Rogov

Paul Sammy

Dan Brown

Sam Altman

3 / 20

Which fork is specific for unlogged tables?

Main fork

Initialization fork

free space map

visiblilty map

4 / 20

What is the purpose of the public schema?

restricted schema for postgres internal usage only

schema used for heterogeneous replication

default schema for user objects

no such schema

5 / 20

TOAST tables reside in a seperate schema?

False

True

6 / 20

What is the purpose of the template0 database?

No such database

Useful for Postgres support Services to debug issues

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

Useful for creating development schemas

7 / 20

What is the process first launched at server start?

postman

postgres

init

pginit

8 / 20

What is the purpose of wal writer?

collects usage statistics for the instance.

flushes dirty pages to disk.

executes checkpoints

writes WAL entries to disk

9 / 20

The pg_default tablespace should never be used to create user tables?

False

True

10 / 20

What is another name for the postgres process?

postmanager

postmaster

aurora

masterprocess

11 / 20

Postgres server spawns a new backend session for each connection?

False

True

12 / 20

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

pg_catalog

pg_class

pg_tables

pg_system

13 / 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

14 / 20

Which of below are predefined schemas?

choose 3

pg_schema

pg_temp

pg_toast

information_schema

15 / 20

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

Schema Path

Access Path

Directory Path

Search Path

16 / 20

Postgres by default has built in connection pooling abilities?

False

True

17 / 20

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

False

True

18 / 20

Files are logically split into pages?

True

False

19 / 20

Which fork keeps track of available space within pages?

used space map

wal space map

free space map

vacuum space map

20 / 20

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

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

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, another transaction modifies this row between these reads and commits the change.

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

2 / 10

The SQL standard specifies three isolation levels?

False

True

3 / 10

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

False

True

4 / 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.

Apply explicit locks

Use a single SQL operator

Replace procedural code with declarative one.

5 / 10

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

False

True

6 / 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 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.

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

7 / 10

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

True

False

8 / 10

Which parameters sets the database default isolation level?

default_transaction_isolation

default_isolation_level

active_transaction_isolation

transaction_isolation_level

9 / 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

reading data direct from memory using pg_dirt

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

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

10 / 10

Which of the below are valid Isolations Levels?

choose 2

Serializable

Rollback Read

Read Committed

Random Scatter

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

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

DELETE

CREATE

COMMIT

INSERT

2 / 10

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

True

False

3 / 10

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

pagesize

pagedetect

pageinspect

pageheadinfo

4 / 10

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

True

False

5 / 10

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

False

True

6 / 10

Tuples can also be referred to as columns?

True

False

7 / 10

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

Each pointer uses 8 bytes

Also know as the pages table of contents

stored in PGDATA/itemptr directory

Each pointer uses 4 bytes

8 / 10

CLOG contains how many bits for each transaction?

9 / 10

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

True

False

10 / 10

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

False

True

Your score is

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