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

What is the purpose of the template0 database?

No such database

Useful for creating development schemas

Useful for Postgres support Services to debug issues

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

2 / 20

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

True

False

3 / 20

What is the purpose of the visibility map?

provides an audit trail for the database

shows referential relationships for tables

shows a page to be vacuumed or frozen

provides the data decryption key

4 / 20

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

False

True

5 / 20

Tablespaces are used to define physical data layout?

True

False

6 / 20

What is the point of the pg_global tablespace?

stores temporary tables that are common to the whole cluster

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

7 / 20

What is the purpose of the public schema?

default schema for user objects

restricted schema for postgres internal usage only

schema used for heterogeneous replication

no such schema

8 / 20

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

Schema Path

Directory Path

Search Path

Access Path

9 / 20

System Catalog tables begin with which prefix?

sys_

cat_

pg_

dba_

10 / 20

Files are logically split into pages?

False

True

11 / 20

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

12 / 20

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

13 / 20

To be able to restore data consistency, Postgres maintains

undo segments (UNDO)

rollback segments (RBS)

write-ahead log (WAL)

online redo logs (ORL)

14 / 20

What is a schema?

This is the same as a user in Postgres

A memory area used to cache data from LRU chains

Namespace that store all objects of a database

The name used to refer to a super user account

15 / 20

A schema can belong to more than one database?

False

True

16 / 20

Who is the Author of the Postgres 14 Internals book?

Dan Brown

Paul Sammy

Egor Rogov

Sam Altman

17 / 20

What is the process first launched at server start?

postman

init

postgres

pginit

18 / 20

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

Choose 2 option

Postgres Server

Aurora

Instance

Quorum

19 / 20

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

free space map

Main fork

table map

visiblilty map

20 / 20

Users should not modify the template0 database

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

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

True

False

2 / 10

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

SAFE

HIPPA

SOC2

ACID

3 / 10

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

False

True

4 / 10

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

Repeatable Read

Read Uncommitted

Read Committed

Serializable

5 / 10

Which of the below are valid Isolations Levels?

choose 2

Serializable

Rollback Read

Read Committed

Random Scatter

6 / 10

The SQL standard specifies three isolation levels?

True

False

7 / 10

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

True

False

8 / 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 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 issue a rollback.

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

9 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

10 / 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

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

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

False

True

2 / 10

UPDATE can be regarded as which 2 separate operations?

MERGE

INSERT

COMMIT

DELETE

3 / 10

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

False

True

4 / 10

Each page has a layer that usually consists of?

choose 2

flashback block

free space

undo segment

page header

5 / 10

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

True

False

6 / 10

If a transaction is read only which kind of Transaction ID is it allocated?

heap XID

magic XID

virtual XID

temporary XID

7 / 10

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

True

False

8 / 10

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

True

False

9 / 10

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

False

True

10 / 10

Information about subtransactions is stored under?

PGDATA/pg_subtrans

PGDATA/subtrans

PGDATA/pg_xid

PGDATA/pg_min

Your score is

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