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

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

False

True

2 / 20

TOAST tables reside in a seperate schema?

False

True

3 / 20

Postgres by default has built in connection pooling abilities?

True

False

4 / 20

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

visiblilty map

free space map

Main fork

table map

5 / 20

What is the purpose of wal writer?

flushes dirty pages to disk.

executes checkpoints

collects usage statistics for the instance.

writes WAL entries to disk

6 / 20

Which fork contains the actual table data?

visiblilty map

table map

free space map

Main fork

7 / 20

Each tablespaces can only be assigned for use by one database

False

True

8 / 20

Who is the Author of the Postgres 14 Internals book?

Paul Sammy

Sam Altman

Egor Rogov

Dan Brown

9 / 20

Which of below are predefined schemas?

choose 3

pg_schema

pg_toast

pg_temp

information_schema

10 / 20

It is the postmasters job to listener for incoming connections?

False

True

11 / 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

12 / 20

What is another name for the postgres process?

aurora

postmaster

postmanager

masterprocess

13 / 20

Postgres server spawns a new backend session for each connection?

False

True

14 / 20

The information_schema schema provides information on Postgres release notes?

False

True

15 / 20

The default Page size is 2k?

False

True

16 / 20

Which of below are predefined schemas?

choose 2

pg_catalog

public

postgres

system

17 / 20

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

18 / 20

A single Postgres Instance can server only one database?

False

True

19 / 20

Which 3 databases exist directly after cluster initialization?

choose 3 options

template0

sysaux

postgres

template1

20 / 20

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

Choose 2 option

Postgres Server

Aurora

Quorum

Instance

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 are valid Isolations Levels?

choose 2

Read Committed

Serializable

Random Scatter

Rollback Read

2 / 10

non-repeatable read anomaly occurs when?

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.

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

3 / 10

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

False

True

4 / 10

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

True

False

5 / 10

Which of the below would best describe a dirty read?

reading data direct from memory using pg_dirt

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

6 / 10

Which parameters sets the database default isolation level?

active_transaction_isolation

default_isolation_level

default_transaction_isolation

transaction_isolation_level

7 / 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

Issues a rollback after the commit to satisfy repeatable read.

Replace procedural code with declarative one.

Use a single SQL operator

8 / 10

A phantom read anomaly occurs when?

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.

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

9 / 10

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

True

False

10 / 10

What is the default Isolation Level?

Read Committed

Serializable

Read Uncommitted

Repeatable Read

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 2 items does a Virtual XID consist of?

xmin

sequential number

backend process ID

checksum

2 / 10

CLOG files are stored in which directory?

PGDATA/pg_xact

PGDATA/pg_clog

PGDATA/clog

PGDATA/pg_commit

3 / 10

UPDATE can be regarded as which 2 separate operations?

MERGE

INSERT

COMMIT

DELETE

4 / 10

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

dump

heap

clog

view

5 / 10

Which function can we use to find the current transaction ID?

pg_current_xact_id()

pg_current_xmin_id()

pg_current_id()

pg_current_commit_id()

6 / 10

What does an Item Pointer contain?

choose 3

tuple offset from the start of the page

tuple xid

tuple length

tuple status

7 / 10

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

False

True

8 / 10

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

True

False

9 / 10

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

Also know as the pages table of contents

stored in PGDATA/itemptr directory

Each pointer uses 8 bytes

Each pointer uses 4 bytes

10 / 10

status of a subtransaction is written into CLOG?

True

False

Your score is

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