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

Which 3 databases exist directly after cluster initialization?

choose 3 options

template1

sysaux

postgres

template0

2 / 20

Which fork keeps track of available space within pages?

vacuum space map

wal space map

used space map

free space map

3 / 20

What is the purpose of wal writer?

writes WAL entries to disk

collects usage statistics for the instance.

flushes dirty pages to disk.

executes checkpoints

4 / 20

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

True

False

5 / 20

What is the purpose of the visibility map?

shows referential relationships for tables

provides an audit trail for the database

provides the data decryption key

shows a page to be vacuumed or frozen

6 / 20

Which fork contains the actual table data?

visiblilty map

free space map

table map

Main fork

7 / 20

System Catalog tables begin with which prefix?

cat_

dba_

pg_

sys_

8 / 20

If we create a new tablespace which directory will symbolic links be created from?

pg_symlinks

pg_tablespace

pg_tabspace

pg_tblspc

9 / 20

Files are logically split into pages?

False

True

10 / 20

Each Database has its own System Catalog?

True

False

11 / 20

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

12 / 20

Which of below are predefined schemas?

choose 3

pg_temp

pg_toast

pg_schema

information_schema

13 / 20

Which of the below objects can be referred to as relations?

choose 3

sequences

triggers

indexes

tables

14 / 20

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

table map

free space map

Main fork

visiblilty map

15 / 20

It is the postmasters job to listener for incoming connections?

True

False

16 / 20

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

pg_class

pg_system

pg_catalog

pg_tables

17 / 20

Who is the Author of the Postgres 14 Internals book?

Dan Brown

Paul Sammy

Sam Altman

Egor Rogov

18 / 20

The information_schema schema provides information on Postgres release notes?

False

True

19 / 20

What is a schema?

The name used to refer to a super user account

A memory area used to cache data from LRU chains

Namespace that store all objects of a database

This is the same as a user in Postgres

20 / 20

What is the default standard size for a fork file?

5MB

5GB

1GB

1MB

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?

Repeatable Read

Read Uncommitted

Serializable

Read Committed

2 / 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.

3 / 10

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

False

True

4 / 10

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

False

True

5 / 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.

6 / 10

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

HIPPA

SAFE

ACID

SOC2

7 / 10

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

True

False

8 / 10

Which of the below are valid Isolations Levels?

choose 2

Random Scatter

Serializable

Read Committed

Rollback Read

9 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

10 / 10

What are some of database features we can use to avoid a non repeatable read?

Select more than 1 answer below:

Replace procedural code with declarative one.

Apply explicit locks

Issues a rollback after the commit to satisfy repeatable read.

Use a single SQL operator

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

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

False

True

2 / 10

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

True

False

3 / 10

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

pageinspect

pagedetect

pageheadinfo

pagesize

4 / 10

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

pg_current_id()

pg_current_commit_id()

pg_current_xact_id()

pg_current_xmin_id()

5 / 10

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

True

False

6 / 10

The page header is located in the highest address?

False

True

7 / 10

virtual IDs exist only in PGDATA/pg_vxid when not cached?

False

True

8 / 10

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

view

clog

dump

heap

9 / 10

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

xmin

xmax

xmas

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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