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

Access Path

Schema Path

Search Path

Directory Path

2 / 20

2. Each Database has its own System Catalog?

False

True

3 / 20

3. Which fork is specific for unlogged tables?

visiblilty map

Main fork

free space map

Initialization fork

4 / 20

4. TOAST tables reside in a seperate schema?

True

False

5 / 20

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

True

False

6 / 20

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

write-ahead log (WAL)

undo segments (UNDO)

online redo logs (ORL)

rollback segments (RBS)

7 / 20

7. 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

8 / 20

8. Which fork contains the actual table data?

Main fork

table map

visiblilty map

free space map

9 / 20

9. What is the name of the catalog that stores metadata for all cluster objects?

System Catalog

Sysaux Catalog

Sysasm Catalog

Sys Catalog

10 / 20

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

table map

Main fork

visiblilty map

free space map

11 / 20

11. What is the purpose of the template1 database?

database used for temporary tables

No such database

regular database that you can use at your discretion

a template for all the other databases

12 / 20

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

True

False

13 / 20

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

pginit

init

postgres

postman

14 / 20

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

BAKE

BREAD

TOAST

GROW

15 / 20

15. What column in system catalogs servers as the Primary Key

oid#

obj#

obj

oid

16 / 20

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

pg_tables

pg_system

pg_catalog

pg_class

17 / 20

17. What is the purpose of the template0 database?

Useful for creating development schemas

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

Useful for Postgres support Services to debug issues

No such database

18 / 20

18. What is the name of the 2 default tablespaces created after initialization?

choose 2

pg_tablespace

pg_temp

pg_default

pg_global

19 / 20

19. What is the point of the pg_global tablespace?

stores temporary tables that are common to the whole cluster

stores WAL logs used for global replication

stores system catalog objects that are common to the whole cluster

stores user tables that are common to the whole cluster

20 / 20

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

PGTIPS

PGCORE

PGBASE

PGDATA

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?

False

True

2 / 10

2. 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

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

3 / 10

3. Which parameters sets the database default isolation level?

default_transaction_isolation

default_isolation_level

active_transaction_isolation

transaction_isolation_level

4 / 10

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

True

False

5 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

6 / 10

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

Read Uncommitted

Repeatable Read

Read Committed

Serializable

7 / 10

7. What is the default Isolation Level?

Read Uncommitted

Serializable

Repeatable Read

Read Committed

8 / 10

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

False

True

9 / 10

9. 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 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 and commits the change.

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. The page header is located in the highest address?

True

False

2 / 10

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

xmas

xmax

xid

xmin

3 / 10

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

False

True

4 / 10

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

heap XID

virtual XID

temporary XID

magic XID

5 / 10

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

DELETE

COMMIT

MERGE

INSERT

6 / 10

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

False

True

7 / 10

7. What does an Item Pointer contain?

choose 3

tuple length

tuple xid

tuple status

tuple offset from the start of the page

8 / 10

8. When a transaction is committed Postgres uses a special <replace with answer> structure?

transaction log

archive log

redo log

commit log

9 / 10

9. Page free space can often become fragmented?

True

False

10 / 10

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

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.