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

Sam Altman

Paul Sammy

Egor Rogov

Dan Brown

2 / 20

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

oid#

oid

obj#

obj

3 / 20

3. A schema can belong to more than one database?

True

False

4 / 20

4. TOAST tables reside in a seperate schema?

False

True

5 / 20

5. What is the purpose of autovacuum?

Performs a backup of WAL logs

Deletes old logs and traces on disk

Removes stale data from tables and indexes

Rebuilds indexes with b level greater than 2

6 / 20

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

False

True

7 / 20

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

False

True

8 / 20

8. What is the purpose of the template1 database?

database used for temporary tables

a template for all the other databases

No such database

regular database that you can use at your discretion

9 / 20

9. Which fork is specific for unlogged tables?

visiblilty map

Initialization fork

Main fork

free space map

10 / 20

10. Which fork contains the actual table data?

visiblilty map

free space map

table map

Main fork

11 / 20

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

choose 2

pg_global

pg_tablespace

pg_temp

pg_default

12 / 20

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

pg_system

pg_catalog

pg_class

pg_tables

13 / 20

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

False

True

14 / 20

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

pginit

init

postman

postgres

15 / 20

15. The default Page size is 2k?

False

True

16 / 20

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

17 / 20

17. What command is used to create the Postgres cluster?

CreatePGC

StartNewPG

CreateCluster

Initialize

18 / 20

18. What is the purpose of the template0 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

No such database

19 / 20

19. System Catalog tables begin with which prefix?

dba_

sys_

pg_

cat_

20 / 20

20. Which of below are predefined schemas?

choose 2

postgres

public

system

pg_catalog

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 are valid Isolations Levels?

choose 2

Random Scatter

Rollback Read

Serializable

Read Committed

2 / 10

2. The SQL standard specifies three isolation levels?

False

True

3 / 10

3. What is the default Isolation Level?

Read Committed

Repeatable Read

Read Uncommitted

Serializable

4 / 10

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

True

False

5 / 10

5. 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 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.

6 / 10

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

True

False

7 / 10

7. 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.

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 also queries this same data.

8 / 10

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

False

True

9 / 10

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

False

True

10 / 10

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

Serializable

Read Committed

Read Uncommitted

Repeatable Read

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?

False

True

2 / 10

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

xid

xmin

xmax

xmas

3 / 10

3. Page free space can often become fragmented?

False

True

4 / 10

4. Which 2 items does a Virtual XID consist of?

checksum

backend process ID

sequential number

xmin

5 / 10

5. indexes do not use row versioning?

False

True

6 / 10

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

False

True

7 / 10

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

heap

view

dump

clog

8 / 10

8. Tuples can also be referred to as columns?

True

False

9 / 10

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

False

True

10 / 10

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

False

True

Your score is

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