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

1. Which of below are predefined schemas?

choose 3

pg_temp

pg_schema

pg_toast

information_schema

2 / 20

2. Postgres server spawns a new backend session for each connection?

True

False

3 / 20

3. Which fork keeps track of available space within pages?

used space map

wal space map

free space map

vacuum space map

4 / 20

4. System Catalog tables begin with which prefix?

pg_

cat_

dba_

sys_

5 / 20

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

True

False

6 / 20

6. What is a schema?

Namespace that store all objects of a database

A memory area used to cache data from LRU chains

This is the same as a user in Postgres

The name used to refer to a super user account

7 / 20

7. Each tablespaces can only be assigned for use by one database

False

True

8 / 20

8. What is the process first launched at server start?

init

pginit

postgres

postman

9 / 20

9. Each Database has its own System Catalog?

True

False

10 / 20

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

True

False

11 / 20

11. What is the purpose of the visibility map?

provides the data decryption key

shows referential relationships for tables

shows a page to be vacuumed or frozen

provides an audit trail for the database

12 / 20

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

Choose 2 option

Quorum

Postgres Server

Aurora

Instance

13 / 20

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

Search Path

Access Path

Schema Path

Directory Path

14 / 20

14. What is the purpose of wal writer?

executes checkpoints

collects usage statistics for the instance.

writes WAL entries to disk

flushes dirty pages to disk.

15 / 20

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

PGTIPS

PGDATA

PGCORE

PGBASE

16 / 20

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

pg_system

pg_catalog

pg_class

pg_tables

17 / 20

17. The default Page size is 2k?

False

True

18 / 20

18. What is another name for the postgres process?

aurora

masterprocess

postmanager

postmaster

19 / 20

19. A single Postgres Instance can server only one database?

False

True

20 / 20

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

free space map

Main fork

table map

visiblilty map

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

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

True

False

2 / 10

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

SOC2

SAFE

ACID

HIPPA

3 / 10

3. Which of the below would best describe a dirty read?

reading data direct from memory using pg_dirt

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

4 / 10

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

Read Committed

Read Uncommitted

Serializable

Repeatable Read

5 / 10

5. 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 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.

6 / 10

6. Which parameters sets the database default isolation level?

default_isolation_level

active_transaction_isolation

default_transaction_isolation

transaction_isolation_level

7 / 10

7. The SQL standard specifies three isolation levels?

True

False

8 / 10

8. 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 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 transactions issues a commit, then a rollback to restore data to its original value

9 / 10

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

Select more than 1 answer below:

Apply explicit locks

Replace procedural code with declarative one.

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

10 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION 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

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

True

False

2 / 10

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

pageheadinfo

pageinspect

pagedetect

pagesize

3 / 10

3. What does an Item Pointer contain?

choose 3

tuple xid

tuple offset from the start of the page

tuple length

tuple status

4 / 10

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

pg_current_xact_id()

pg_current_commit_id()

pg_current_id()

pg_current_xmin_id()

5 / 10

5. CLOG contains how many bits for each transaction?

6 / 10

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

True

False

7 / 10

7. Which 2 items does a Virtual XID consist of?

sequential number

xmin

checksum

backend process ID

8 / 10

8. Page free space can often become fragmented?

True

False

9 / 10

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

virtual XID

heap XID

magic XID

temporary XID

10 / 10

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

xmin

xmas

xid

xmax

Your score is

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