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. Which of below are predefined schemas?

choose 3

pg_toast

pg_temp

pg_schema

information_schema

2 / 20

2. 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

3 / 20

3. Which 3 databases exist directly after cluster initialization?

choose 3 options

postgres

template1

template0

sysaux

4 / 20

4. System Catalog tables begin with which prefix?

sys_

pg_

dba_

cat_

5 / 20

5. What is a schema?

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

This is the same as a user in Postgres

6 / 20

6. Which of below are predefined schemas?

choose 2

pg_catalog

public

system

postgres

7 / 20

7. What is another name for the postgres process?

masterprocess

postmaster

aurora

postmanager

8 / 20

8. What is the purpose of wal writer?

collects usage statistics for the instance.

flushes dirty pages to disk.

executes checkpoints

writes WAL entries to disk

9 / 20

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

False

True

10 / 20

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

table map

Main fork

visiblilty map

free space map

11 / 20

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

False

True

12 / 20

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

False

True

13 / 20

13. What is the purpose of the postgres database?

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

regular database that you can use at your discretion

No such database

a template for all the other database

14 / 20

14. The default Page size is 2k?

True

False

15 / 20

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

False

True

16 / 20

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

True

False

17 / 20

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

free space map

wal space map

vacuum space map

used space map

18 / 20

18. Each Database has its own System Catalog?

True

False

19 / 20

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

init

postgres

postman

pginit

20 / 20

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

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 parameters sets the database default isolation level?

active_transaction_isolation

default_isolation_level

transaction_isolation_level

default_transaction_isolation

2 / 10

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

False

True

3 / 10

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

False

True

4 / 10

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

SAFE

HIPPA

SOC2

ACID

5 / 10

5. Based on Snapshot Isolation use of MVCC which of the below are permitted?

choose 3

Repeatable Read

Serializable

Read Committed

Read Uncommitted

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 uncommited data altered by another session

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

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

7 / 10

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

False

True

8 / 10

8. non-repeatable read anomaly occurs when?

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, 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.

A transaction reads one and the same row once and modifies this row and commits the change.

9 / 10

9. Which of the below are valid Isolations Levels?

choose 2

Random Scatter

Serializable

Rollback Read

Read Committed

10 / 10

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

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

Also know as the pages table of contents

Each pointer uses 4 bytes

Each pointer uses 8 bytes

stored in PGDATA/itemptr directory

2 / 10

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

False

True

3 / 10

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

choose 2

page header

undo segment

flashback block

free space

4 / 10

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

True

False

5 / 10

5. What does an Item Pointer contain?

choose 3

tuple length

tuple xid

tuple offset from the start of the page

tuple status

6 / 10

6. CLOG Pages are never cached in memory?

False

True

7 / 10

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

False

True

8 / 10

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

True

False

9 / 10

9. status of a subtransaction is written into CLOG?

True

False

10 / 10

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

pg_current_xmin_id()

pg_current_xact_id()

pg_current_id()

pg_current_commit_id()

Your score is

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