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

True

False

2 / 20

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

Directory Path

Access Path

Schema Path

Search Path

3 / 20

3. The default Page size is 2k?

True

False

4 / 20

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

Main fork

visiblilty map

table map

free space map

5 / 20

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

True

False

6 / 20

6. Users should not modify the template0 database

False

True

7 / 20

7. What is the purpose of the template0 database?

No such database

Useful for Postgres support Services to debug issues

Useful for creating development schemas

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

8 / 20

8. Which of below are predefined schemas?

choose 2

postgres

system

pg_catalog

public

9 / 20

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

False

True

10 / 20

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

True

False

11 / 20

11. What is the purpose of the public schema?

default schema for user objects

schema used for heterogeneous replication

restricted schema for postgres internal usage only

no such schema

12 / 20

12. Which of below are predefined schemas?

choose 3

pg_schema

pg_toast

pg_temp

information_schema

13 / 20

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

Egor Rogov

Dan Brown

Paul Sammy

Sam Altman

14 / 20

14. Files are logically split into pages?

False

True

15 / 20

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

False

True

16 / 20

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

choose 2

pg_default

pg_temp

pg_tablespace

pg_global

17 / 20

17. What is the purpose of the visibility map?

shows a page to be vacuumed or frozen

provides an audit trail for the database

shows referential relationships for tables

provides the data decryption key

18 / 20

18. What is the purpose of the template1 database?

regular database that you can use at your discretion

database used for temporary tables

No such database

a template for all the other databases

19 / 20

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

True

False

20 / 20

20. pg_catalog schema is used to store system catalog 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. At any moment the database system can contain several versions of one and the same row?

True

False

2 / 10

2. 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 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 transactions issues a commit, then a rollback to restore data to its original value

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

3 / 10

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

False

True

4 / 10

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

True

False

5 / 10

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

False

True

6 / 10

6. non-repeatable read anomaly occurs when?

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.

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.

7 / 10

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

SAFE

ACID

SOC2

HIPPA

8 / 10

8. 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

Issues a rollback after the commit to satisfy repeatable read.

Use a single SQL operator

9 / 10

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

reading data direct from memory using pg_dirt

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

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

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

10 / 10

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

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. Each page has a layer that usually consists of?

choose 2

free space

flashback block

undo segment

page header

2 / 10

2. indexes do not use row versioning?

False

True

3 / 10

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

False

True

4 / 10

4. status of a subtransaction is written into CLOG?

True

False

5 / 10

5. What does an Item Pointer contain?

choose 3

tuple xid

tuple length

tuple status

tuple offset from the start of the page

6 / 10

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

True

False

7 / 10

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

False

True

8 / 10

8. In Postgres, tables are often referred to as which of the below?

heap

clog

dump

view

9 / 10

9. 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

10 / 10

10. CLOG contains how many bits for each transaction?

Your score is

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