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 process first launched at server start?

postgres

pginit

init

postman

2 / 20

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

rollback segments (RBS)

online redo logs (ORL)

undo segments (UNDO)

write-ahead log (WAL)

3 / 20

3. What is a schema?

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

Namespace that store all objects of a database

4 / 20

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

True

False

5 / 20

5. Postgres uses a thread based process model?

False

True

6 / 20

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

TOAST

BREAD

BAKE

GROW

7 / 20

7. Which fork is specific for unlogged tables?

visiblilty map

free space map

Initialization fork

Main fork

8 / 20

8. Tablespaces can be used to segregate data based on performance needs?

True

False

9 / 20

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

False

True

10 / 20

10. What is the purpose of the visibility map?

shows referential relationships for tables

provides the data decryption key

provides an audit trail for the database

shows a page to be vacuumed or frozen

11 / 20

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

choose 3

indexes

sequences

tables

triggers

12 / 20

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

5GB

5MB

1MB

1GB

13 / 20

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

False

True

14 / 20

14. Which of below are predefined schemas?

choose 3

pg_schema

pg_toast

pg_temp

information_schema

15 / 20

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

16 / 20

16. Each Database has its own System Catalog?

False

True

17 / 20

17. What is the purpose of autovacuum?

Performs a backup of WAL logs

Rebuilds indexes with b level greater than 2

Deletes old logs and traces on disk

Removes stale data from tables and indexes

18 / 20

18. Which fork contains the actual table data?

table map

visiblilty map

free space map

Main fork

19 / 20

19. Users should not modify the template0 database

True

False

20 / 20

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

pg_tabspace

pg_tblspc

pg_tablespace

pg_symlinks

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. 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.

2 / 10

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

True

False

3 / 10

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

True

False

4 / 10

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

False

True

5 / 10

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

True

False

6 / 10

6. non-repeatable read anomaly occurs when?

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.

A transaction reads one and the same row twice, another transaction modifies this row between these reads issue a rollback.

7 / 10

7. 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

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

8 / 10

8. The SQL standard specifies three isolation levels?

True

False

9 / 10

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

False

True

10 / 10

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

SAFE

HIPPA

ACID

SOC2

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

True

False

2 / 10

2. What does an Item Pointer contain?

choose 3

tuple offset from the start of the page

tuple xid

tuple status

tuple length

3 / 10

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

pageheadinfo

pagedetect

pageinspect

pagesize

4 / 10

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

True

False

5 / 10

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

Each pointer uses 4 bytes

stored in PGDATA/itemptr directory

Each pointer uses 8 bytes

Also know as the pages table of contents

6 / 10

6. CLOG files are stored in which directory?

PGDATA/pg_commit

PGDATA/pg_clog

PGDATA/pg_xact

PGDATA/clog

7 / 10

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

False

True

8 / 10

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

True

False

9 / 10

9. The page Special Space is located at the start of the page with highest address

False

True

10 / 10

10. A page along with its tuples is read into the buffer cache with compression transformations to enhance cache efficiency?

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.