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. TOAST tables reside in a seperate schema?

True

False

2 / 20

2. A schema can belong to more than one database?

False

True

3 / 20

3. The information_schema schema provides information on Postgres release notes?

True

False

4 / 20

4. To be able to restore data consistency, Postgres maintains

rollback segments (RBS)

online redo logs (ORL)

write-ahead log (WAL)

undo segments (UNDO)

5 / 20

5. pg_catalog schema is used to store system catalog tables?

True

False

6 / 20

6. To understand each other, a client and a server must use one and the same interfacing protocol?

False

True

7 / 20

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

8 / 20

8. Which 3 databases exist directly after cluster initialization?

choose 3 options

template0

sysaux

template1

postgres

9 / 20

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

False

True

10 / 20

10. What is the purpose of the visibility map?

shows a page to be vacuumed or frozen

shows referential relationships for tables

provides the data decryption key

provides an audit trail for the database

11 / 20

11. Postgres by default has built in connection pooling abilities?

False

True

12 / 20

12. Who is the Author of the Postgres 14 Internals book?

Sam Altman

Paul Sammy

Dan Brown

Egor Rogov

13 / 20

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

True

False

14 / 20

14. What is the purpose of the postgres database?

a template for all the other database

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

No such database

regular database that you can use at your discretion

15 / 20

15. The default Page size is 2k?

True

False

16 / 20

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

pg_class

pg_catalog

pg_system

pg_tables

17 / 20

17. What is the purpose of autovacuum?

Removes stale data from tables and indexes

Performs a backup of WAL logs

Deletes old logs and traces on disk

Rebuilds indexes with b level greater than 2

18 / 20

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

True

False

19 / 20

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

PGCORE

PGDATA

PGBASE

PGTIPS

20 / 20

20. Each Database has its own System Catalog?

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

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

False

True

2 / 10

2. 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

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

reading the data directly from file using a text editor such as vi or notepad

3 / 10

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

False

True

4 / 10

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

choose 3

Serializable

Read Committed

Read Uncommitted

Repeatable Read

5 / 10

5. The SQL standard specifies three isolation levels?

True

False

6 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

7 / 10

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

False

True

8 / 10

8. 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.

Use a single SQL operator

Apply explicit locks

Replace procedural code with declarative one.

9 / 10

9. 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 also queries this same data.

A transactions inserts a null value into a not null columns 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 adds some other rows satisfying this condition and commits.

10 / 10

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

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

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

True

False

2 / 10

2. UPDATE can be regarded as which 2 separate operations?

DELETE

MERGE

INSERT

COMMIT

3 / 10

3. Which of the below are true about a Pages Item Pointer?

Each pointer uses 4 bytes

Each pointer uses 8 bytes

stored in PGDATA/itemptr directory

Also know as the pages table of contents

4 / 10

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

False

True

5 / 10

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

pageinspect

pageheadinfo

pagedetect

pagesize

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. The page header stores checksum and the sizes of the other parts of the page?

True

False

8 / 10

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

pg_current_xmin_id()

pg_current_xact_id()

pg_current_id()

pg_current_commit_id()

9 / 10

9. Page free space can often become fragmented?

True

False

10 / 10

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

False

True

Your score is

Cookie	Duration	Description
cookielawinfo-checkbox-analytics	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Analytics".
cookielawinfo-checkbox-functional	11 months	The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional".
cookielawinfo-checkbox-necessary	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookies is used to store the user consent for the cookies in the category "Necessary".
cookielawinfo-checkbox-others	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Other.
cookielawinfo-checkbox-performance	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Performance".
viewed_cookie_policy	11 months	The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. It does not store any personal data.