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

True

False

2 / 20

2. What is the purpose of the public schema?

default schema for user objects

schema used for heterogeneous replication

no such schema

restricted schema for postgres internal usage only

3 / 20

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

Directory Path

Schema Path

Search Path

Access Path

4 / 20

4. What is the purpose of the visibility map?

shows a page to be vacuumed or frozen

provides the data decryption key

shows referential relationships for tables

provides an audit trail for the database

5 / 20

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

6 / 20

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

True

False

7 / 20

7. TOAST tables reside in a seperate schema?

False

True

8 / 20

8. Which of below are predefined schemas?

choose 3

pg_temp

pg_toast

information_schema

pg_schema

9 / 20

9. What is a schema?

The name used to refer to a super user account

A memory area used to cache data from LRU chains

This is the same as a user in Postgres

Namespace that store all objects of a database

10 / 20

10. Which 3 databases exist directly after cluster initialization?

choose 3 options

sysaux

postgres

template1

template0

11 / 20

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

False

True

12 / 20

12. Users should not modify the template0 database

True

False

13 / 20

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

free space map

used space map

wal space map

vacuum space map

14 / 20

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

True

False

15 / 20

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

postgres

postman

pginit

init

16 / 20

16. What is the purpose of wal writer?

flushes dirty pages to disk.

writes WAL entries to disk

collects usage statistics for the instance.

executes checkpoints

17 / 20

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

1GB

5MB

5GB

1MB

18 / 20

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

visiblilty map

table map

free space map

Main fork

19 / 20

19. What is the purpose of the postgres database?

No such database

regular database that you can use at your discretion

a template for all the other database

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

20 / 20

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

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

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

2 / 10

2. 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.

3 / 10

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

False

True

4 / 10

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

True

False

5 / 10

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

True

False

6 / 10

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

reading data direct from memory using pg_dirt

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

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

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

7 / 10

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

SOC2

ACID

SAFE

HIPPA

8 / 10

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

False

True

9 / 10

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

True

False

10 / 10

10. 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 also queries this same data.

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

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

False

True

2 / 10

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

True

False

3 / 10

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

True

False

4 / 10

4. Postgres table physical data files are always cross compatible across platforms?

True

False

5 / 10

5. CLOG files are stored in which directory?

PGDATA/clog

PGDATA/pg_commit

PGDATA/pg_clog

PGDATA/pg_xact

6 / 10

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

choose 2

flashback block

free space

undo segment

page header

7 / 10

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

True

False

8 / 10

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

heap

clog

dump

view

9 / 10

9. Which function can we use to find the current transaction ID?

pg_current_xact_id()

pg_current_commit_id()

pg_current_xmin_id()

pg_current_id()

10 / 10

10. CLOG Pages are never cached in memory?

True

False

Your score is

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