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 are used to define physical data layout?

True

False

2 / 20

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

False

True

3 / 20

3. Which fork contains the actual table data?

visiblilty map

Main fork

table map

free space map

4 / 20

4. The default Page size is 2k?

True

False

5 / 20

5. It is the postmasters job to listener for incoming connections?

False

True

6 / 20

6. What is the purpose of the visibility map?

shows referential relationships for tables

shows a page to be vacuumed or frozen

provides an audit trail for the database

provides the data decryption key

7 / 20

7. What is the purpose of the template1 database?

database used for temporary tables

a template for all the other databases

regular database that you can use at your discretion

No such database

8 / 20

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

Paul Sammy

Egor Rogov

Sam Altman

Dan Brown

9 / 20

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

free space map

Main fork

visiblilty map

table map

10 / 20

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

pg_tables

pg_system

pg_catalog

pg_class

11 / 20

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

init

postgres

pginit

postman

12 / 20

12. Which of below are predefined schemas?

choose 2

public

system

postgres

pg_catalog

13 / 20

13. What is the purpose of the template0 database?

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

No such database

Useful for Postgres support Services to debug issues

Useful for creating development schemas

14 / 20

14. pg_catalog schema is used to store system catalog tables?

False

True

15 / 20

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

Sysasm Catalog

Sys Catalog

Sysaux Catalog

System Catalog

16 / 20

16. When PostgreSQL is running what can it be referred to as?

Choose 2 option

Aurora

Quorum

Postgres Server

Instance

17 / 20

17. What is the purpose of autovacuum?

Deletes old logs and traces on disk

Rebuilds indexes with b level greater than 2

Performs a backup of WAL logs

Removes stale data from tables and indexes

18 / 20

18. What is a schema?

This is the same as a user in Postgres

A memory area used to cache data from LRU chains

The name used to refer to a super user account

Namespace that store all objects of a database

19 / 20

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

obj#

obj

oid#

oid

20 / 20

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

Access Path

Directory Path

Schema Path

Search Path

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 would best describe a dirty read?

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

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

2 / 10

2. Which of the below are valid Isolations Levels?

choose 2

Read Committed

Serializable

Random Scatter

Rollback Read

3 / 10

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

False

True

4 / 10

4. A phantom read anomaly occurs when?

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 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.

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

5 / 10

5. Which parameters sets the database default isolation level?

transaction_isolation_level

active_transaction_isolation

default_isolation_level

default_transaction_isolation

6 / 10

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

False

True

7 / 10

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

Read Uncommitted

Serializable

Read Committed

Repeatable Read

8 / 10

8. The SQL standard specifies three isolation levels?

True

False

9 / 10

9. What are some of database features we can use to avoid a non repeatable read?

Select more than 1 answer below:

Apply explicit locks

Issues a rollback after the commit to satisfy repeatable read.

Use a single SQL operator

Replace procedural code with declarative one.

10 / 10

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

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. a transaction containing a savepoint is will still be considered as only a single transaction?

True

False

2 / 10

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

False

True

3 / 10

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

False

True

4 / 10

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

False

True

5 / 10

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

True

False

6 / 10

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

view

clog

dump

heap

7 / 10

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

choose 2

undo segment

flashback block

page header

free space

8 / 10

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

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. What does an Item Pointer contain?

choose 3

tuple offset from the start of the page

tuple status

tuple length

tuple xid

Your score is

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