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. What is the name of the mechanism used to store a row bigger than a page size?

TOAST

BAKE

BREAD

GROW

2 / 20

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

Sam Altman

Paul Sammy

Egor Rogov

Dan Brown

3 / 20

3. Files are logically split into pages?

True

False

4 / 20

4. What command is used to create the Postgres cluster?

CreatePGC

Initialize

StartNewPG

CreateCluster

5 / 20

5. What is the purpose of the template1 database?

No such database

a template for all the other databases

regular database that you can use at your discretion

database used for temporary tables

6 / 20

6. What is the purpose of the visibility map?

shows a page to be vacuumed or frozen

provides the data decryption key

provides an audit trail for the database

shows referential relationships for tables

7 / 20

7. Users should not modify the template0 database

False

True

8 / 20

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

choose 3

sequences

indexes

tables

triggers

9 / 20

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

False

True

10 / 20

10. Which fork is specific for unlogged tables?

visiblilty map

Main fork

free space map

Initialization fork

11 / 20

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

vacuum space map

wal space map

used space map

free space map

12 / 20

12. What is the default standard size for a fork file?

5GB

1MB

5MB

1GB

13 / 20

13. Tablespaces are used to define physical data layout?

True

False

14 / 20

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

True

False

15 / 20

15. System Catalog tables begin with which prefix?

dba_

pg_

cat_

sys_

16 / 20

16. What is the point of the pg_global tablespace?

stores system catalog objects that are common to the whole cluster

stores WAL logs used for global replication

stores user tables that are common to the whole cluster

stores temporary tables that are common to the whole cluster

17 / 20

17. Each Database has its own System Catalog?

True

False

18 / 20

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

PGTIPS

PGBASE

PGCORE

PGDATA

19 / 20

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

pg_tblspc

pg_symlinks

pg_tablespace

pg_tabspace

20 / 20

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

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. 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.

2 / 10

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

choose 3

Repeatable Read

Serializable

Read Committed

Read Uncommitted

3 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

4 / 10

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

False

True

5 / 10

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

True

False

6 / 10

6. A phantom read anomaly occurs when?

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.

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.

A transactions inserts a null value into a not null columns and commits

7 / 10

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

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

reading data direct from memory using pg_dirt

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

8 / 10

8. What is the default Isolation Level?

Repeatable Read

Serializable

Read Committed

Read Uncommitted

9 / 10

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

False

True

10 / 10

10. The SQL standard specifies three isolation levels?

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. UPDATE can be regarded as which 2 separate operations?

MERGE

INSERT

COMMIT

DELETE

2 / 10

2. Each page has a layer that usually consists of?

choose 2

free space

page header

undo segment

flashback block

3 / 10

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

False

True

4 / 10

4. status of a subtransaction is written into CLOG?

False

True

5 / 10

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

False

True

6 / 10

6. CLOG files are stored in which directory?

PGDATA/pg_commit

PGDATA/pg_clog

PGDATA/pg_xact

PGDATA/clog

7 / 10

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

False

True

8 / 10

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

False

True

9 / 10

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

False

True

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

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.