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. What is the process first launched at server start?

init

postgres

postman

pginit

2 / 20

2. Users should not modify the template0 database

False

True

3 / 20

3. Which of the below objects can be referred to as relations?

choose 3

tables

indexes

triggers

sequences

4 / 20

4. What is the purpose of the template1 database?

No such database

database used for temporary tables

a template for all the other databases

regular database that you can use at your discretion

5 / 20

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

False

True

6 / 20

6. What is a schema?

The name used to refer to a super user account

Namespace that store all objects of a database

A memory area used to cache data from LRU chains

This is the same as a user in Postgres

7 / 20

7. System Catalog tables begin with which prefix?

dba_

pg_

sys_

cat_

8 / 20

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

False

True

9 / 20

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

True

False

10 / 20

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

False

True

11 / 20

11. What is the purpose of the postgres database?

regular database that you can use at your discretion

No such database

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

a template for all the other database

12 / 20

12. To be able to restore data consistency, Postgres maintains

online redo logs (ORL)

write-ahead log (WAL)

rollback segments (RBS)

undo segments (UNDO)

13 / 20

13. What is the purpose of wal writer?

flushes dirty pages to disk.

collects usage statistics for the instance.

writes WAL entries to disk

executes checkpoints

14 / 20

14. What is the name of the mechanism used to store a row bigger than a page size?

BAKE

BREAD

GROW

TOAST

15 / 20

15. What is the purpose of autovacuum?

Deletes old logs and traces on disk

Removes stale data from tables and indexes

Rebuilds indexes with b level greater than 2

Performs a backup of WAL logs

16 / 20

16. Which 3 databases exist directly after cluster initialization?

choose 3 options

template0

sysaux

postgres

template1

17 / 20

17. What is another name for the postgres process?

masterprocess

postmanager

aurora

postmaster

18 / 20

18. Which of below are predefined schemas?

choose 2

postgres

pg_catalog

system

public

19 / 20

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

False

True

20 / 20

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

oid#

obj

oid

obj#

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

Serializable

Read Committed

Random Scatter

Rollback Read

2 / 10

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

Serializable

Read Committed

Repeatable Read

Read Uncommitted

3 / 10

3. Which parameters sets the database default isolation level?

default_transaction_isolation

transaction_isolation_level

default_isolation_level

active_transaction_isolation

4 / 10

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

True

False

5 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

6 / 10

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

False

True

7 / 10

7. non-repeatable read anomaly occurs when?

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 once and modifies this row and commits the change.

A transaction reads one and the same row twice, another transaction modifies this row between these reads issue a rollback.

8 / 10

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

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 data direct from memory using pg_dirt

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

9 / 10

9. The SQL standard specifies three isolation levels?

False

True

10 / 10

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

Select more than 1 answer below:

Issues a rollback after the commit to satisfy repeatable read.

Use a single SQL operator

Replace procedural code with declarative one.

Apply explicit locks

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

heap

clog

dump

view

2 / 10

2. CLOG Pages are never cached in memory?

False

True

3 / 10

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

True

False

4 / 10

4. status of a subtransaction is written into CLOG?

False

True

5 / 10

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

False

True

6 / 10

6. When a row is created, its xmin value is set to the transaction ID of which command?

COMMIT

INSERT

DELETE

CREATE

7 / 10

7. Page header sizes can be easily displayed using the <choose from answers> extension

pagedetect

pagesize

pageinspect

pageheadinfo

8 / 10

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

Each pointer uses 8 bytes

stored in PGDATA/itemptr directory

Each pointer uses 4 bytes

Also know as the pages table of contents

9 / 10

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

True

False

10 / 10

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

choose 2

page header

undo segment

flashback block

free space

Your score is

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