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 name of the system catalog table for relations?

pg_system

pg_catalog

pg_class

pg_tables

2 / 20

To be able to restore data consistency, Postgres maintains

write-ahead log (WAL)

undo segments (UNDO)

rollback segments (RBS)

online redo logs (ORL)

3 / 20

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

visiblilty map

Main fork

free space map

table map

4 / 20

What command is used to create the Postgres cluster?

Initialize

CreateCluster

StartNewPG

CreatePGC

5 / 20

Tablespaces are used to define physical data layout?

True

False

6 / 20

Which fork contains the actual table data?

visiblilty map

free space map

table map

Main fork

7 / 20

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

False

True

8 / 20

A schema can belong to more than one database?

False

True

9 / 20

What is the default standard size for a fork file?

1MB

5GB

1GB

5MB

10 / 20

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

Choose 2 option

Instance

Aurora

Postgres Server

Quorum

11 / 20

What is the purpose of the template0 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

No such database

12 / 20

What is the name of the directory that contains the files related to the Postgres cluster?

PGDATA

PGCORE

PGTIPS

PGBASE

13 / 20

Each tablespaces can only be assigned for use by one database

True

False

14 / 20

The default Page size is 2k?

True

False

15 / 20

Who is the Author of the Postgres 14 Internals book?

Dan Brown

Sam Altman

Paul Sammy

Egor Rogov

16 / 20

Which fork keeps track of available space within pages?

used space map

wal space map

vacuum space map

free space map

17 / 20

pg_catalog schema is used to store system catalog tables?

False

True

18 / 20

What is the purpose of the template1 database?

database used for temporary tables

regular database that you can use at your discretion

No such database

a template for all the other databases

19 / 20

Which fork is specific for unlogged tables?

Main fork

visiblilty map

free space map

Initialization fork

20 / 20

Users should not modify the template0 database

False

True

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?

False

True

2 / 10

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

False

True

3 / 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

Replace procedural code with declarative one.

Use a single SQL operator

4 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

5 / 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 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

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.

6 / 10

Which of the below are valid Isolations Levels?

choose 2

Read Committed

Rollback Read

Random Scatter

Serializable

7 / 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 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.

8 / 10

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

SOC2

SAFE

HIPPA

ACID

9 / 10

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

choose 3

Read Committed

Repeatable Read

Serializable

Read Uncommitted

10 / 10

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

False

True

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

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

xmin

xmas

xmax

xid

2 / 10

indexes do not use row versioning?

True

False

3 / 10

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

pagesize

pagedetect

pageheadinfo

pageinspect

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

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

redo log

archive log

transaction log

commit log

6 / 10

status of a subtransaction is written into CLOG?

True

False

7 / 10

CLOG files are stored in which directory?

PGDATA/pg_commit

PGDATA/pg_clog

PGDATA/pg_xact

PGDATA/clog

8 / 10

Tuples can also be referred to as columns?

False

True

9 / 10

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

heap XID

magic XID

virtual XID

temporary XID

10 / 10

psql provides a special mode that allows you to continue a transaction after a failure?

True

False

Your score is

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