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 column in system catalogs servers as the Primary Key

obj

oid

oid#

obj#

2 / 20

2. Users should not modify the template0 database

False

True

3 / 20

3. What is the purpose of the public schema?

restricted schema for postgres internal usage only

default schema for user objects

schema used for heterogeneous replication

no such schema

4 / 20

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

1MB

5GB

5MB

1GB

5 / 20

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

choose 2

pg_global

pg_tablespace

pg_default

pg_temp

6 / 20

6. How many rows in a page does Postgres aim to have before considering TOAST?

7 / 20

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

True

False

8 / 20

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

table map

visiblilty map

Main fork

free space map

9 / 20

9. What is the purpose of the postgres database?

a template for all the other database

No such database

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

regular database that you can use at your discretion

10 / 20

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

PGBASE

PGTIPS

PGDATA

PGCORE

11 / 20

11. What is the point of the pg_global tablespace?

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

stores temporary tables that are common to the whole cluster

12 / 20

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

pg_catalog

pg_tables

pg_system

pg_class

13 / 20

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

True

False

14 / 20

14. Files are logically split into pages?

False

True

15 / 20

15. What is the purpose of the template1 database?

No such database

database used for temporary tables

regular database that you can use at your discretion

a template for all the other databases

16 / 20

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

postman

init

postgres

pginit

17 / 20

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

Paul Sammy

Dan Brown

Egor Rogov

Sam Altman

18 / 20

18. What is the purpose of the template0 database?

Useful for creating development schemas

Useful for Postgres support Services to debug issues

No such database

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

19 / 20

19. Which 3 databases exist directly after cluster initialization?

choose 3 options

template0

template1

postgres

sysaux

20 / 20

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

True

False

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 is the default Isolation Level?

Read Committed

Serializable

Repeatable Read

Read Uncommitted

2 / 10

2. 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 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.

3 / 10

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

False

True

4 / 10

4. 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

Replace procedural code with declarative one.

Apply explicit locks

5 / 10

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

HIPPA

SOC2

SAFE

ACID

6 / 10

6. Which of the below are valid Isolations Levels?

choose 2

Read Committed

Rollback Read

Random Scatter

Serializable

7 / 10

7. 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 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 once, another transaction modifies this row between these reads and commits the change.

8 / 10

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

True

False

9 / 10

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

False

True

10 / 10

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

True

False

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

False

True

2 / 10

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

True

False

3 / 10

3. CLOG Pages are never cached in memory?

False

True

4 / 10

4. Tuples can also be referred to as columns?

False

True

5 / 10

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

pagedetect

pageheadinfo

pagesize

pageinspect

6 / 10

6. The page header is located in the highest address?

False

True

7 / 10

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

Each pointer uses 8 bytes

stored in PGDATA/itemptr directory

Also know as the pages table of contents

Each pointer uses 4 bytes

8 / 10

8. When a row is created, its xmin value is set to the transaction ID of which command?

INSERT

DELETE

CREATE

COMMIT

9 / 10

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

True

False

10 / 10

10. indexes do not use row versioning?

True

False

Your score is

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