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 visibility map?

shows referential relationships for tables

provides the data decryption key

shows a page to be vacuumed or frozen

provides an audit trail for the database

2 / 20

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

pg_system

pg_class

pg_tables

pg_catalog

3 / 20

Postgres by default has built in connection pooling abilities?

False

True

4 / 20

A Postgres cluster consists of 2 or more physical servers accessing one Postgres Instance?

True

False

5 / 20

pg_catalog schema is used to store system catalog tables?

False

True

6 / 20

A single Postgres Instance can server only one database?

False

True

7 / 20

Which fork contains the actual table data?

visiblilty map

free space map

table map

Main fork

8 / 20

What is the purpose of the public schema?

no such schema

schema used for heterogeneous replication

default schema for user objects

restricted schema for postgres internal usage only

9 / 20

Users should not modify the template0 database

True

False

10 / 20

Who is the Author of the Postgres 14 Internals book?

Paul Sammy

Dan Brown

Sam Altman

Egor Rogov

11 / 20

Tablespaces can be used to segregate data based on performance needs?

True

False

12 / 20

Postgres uses a thread based process model?

True

False

13 / 20

What is the purpose of the template0 database?

Useful for creating development schemas

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

14 / 20

What is another name for the postgres process?

postmaster

aurora

masterprocess

postmanager

15 / 20

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

Choose 2 option

Quorum

Postgres Server

Aurora

Instance

16 / 20

Which of below are predefined schemas?

choose 3

pg_toast

pg_schema

pg_temp

information_schema

17 / 20

To be able to restore data consistency, Postgres maintains

write-ahead log (WAL)

online redo logs (ORL)

rollback segments (RBS)

undo segments (UNDO)

18 / 20

Which 3 databases exist directly after cluster initialization?

choose 3 options

template0

postgres

sysaux

template1

19 / 20

Which of below are predefined schemas?

choose 2

postgres

pg_catalog

public

system

20 / 20

What is the purpose of autovacuum?

Rebuilds indexes with b level greater than 2

Performs a backup of WAL logs

Removes stale data from tables and indexes

Deletes old logs and traces on disk

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

Read Uncommitted

Serializable

Repeatable Read

Read Committed

2 / 10

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

False

True

3 / 10

non-repeatable read anomaly occurs when?

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.

A transaction reads one and the same row twice, another transaction modifies this row between these reads issue a rollback.

4 / 10

Which of the below are valid Isolations Levels?

choose 2

Serializable

Read Committed

Random Scatter

Rollback Read

5 / 10

Which of the below would best describe a dirty read?

reading data direct from memory using pg_dirt

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

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

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 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 also queries this same data.

7 / 10

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

False

True

8 / 10

Which parameters sets the database default isolation level?

active_transaction_isolation

default_isolation_level

transaction_isolation_level

default_transaction_isolation

9 / 10

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

SOC2

SAFE

ACID

HIPPA

10 / 10

The SQL standard specifies three isolation levels?

True

False

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?

backend process ID

xmin

sequential number

checksum

2 / 10

When a transaction is committed Postgres uses a special <replace with answer> structure?

redo log

transaction log

commit log

archive log

3 / 10

CLOG files are stored in which directory?

PGDATA/pg_xact

PGDATA/pg_commit

PGDATA/pg_clog

PGDATA/clog

4 / 10

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

pg_current_commit_id()

pg_current_id()

pg_current_xmin_id()

pg_current_xact_id()

5 / 10

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

False

True

6 / 10

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

True

False

7 / 10

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

pagesize

pageinspect

pagedetect

pageheadinfo

8 / 10

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

False

True

9 / 10

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

True

False

10 / 10

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

xmin

xid

xmax

xmas

Your score is

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