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 2

postgres

pg_catalog

system

public

2 / 20

2. Users should not modify the template0 database

True

False

3 / 20

3. What is the purpose of the public schema?

schema used for heterogeneous replication

default schema for user objects

restricted schema for postgres internal usage only

no such schema

4 / 20

4. What is the point of the pg_global tablespace?

stores temporary tables that are common to the whole cluster

stores user tables that are common to the whole cluster

stores WAL logs used for global replication

stores system catalog objects that are common to the whole cluster

5 / 20

5. What is the name of the directory that contains the files related to the Postgres cluster?

PGTIPS

PGCORE

PGDATA

PGBASE

6 / 20

6. Some System Catalog tables are common to all databases in the cluster?

True

False

7 / 20

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

8 / 20

8. If we create a new tablespace which directory will symbolic links be created from?

pg_tabspace

pg_tablespace

pg_tblspc

pg_symlinks

9 / 20

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

True

False

10 / 20

10. What is another name for the postgres process?

postmanager

postmaster

aurora

masterprocess

11 / 20

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

12 / 20

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

True

False

13 / 20

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

rollback segments (RBS)

undo segments (UNDO)

online redo logs (ORL)

write-ahead log (WAL)

14 / 20

14. What is the purpose of wal writer?

executes checkpoints

flushes dirty pages to disk.

collects usage statistics for the instance.

writes WAL entries to disk

15 / 20

15. What is the purpose of the postgres database?

a template for all the other database

No such database

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

regular database that you can use at your discretion

16 / 20

16. Postgres uses a thread based process model?

False

True

17 / 20

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

choose 3

indexes

tables

sequences

triggers

18 / 20

18. The default Page size is 2k?

False

True

19 / 20

19. Which fork contains the actual table data?

table map

visiblilty map

free space map

Main fork

20 / 20

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

free space map

visiblilty map

table map

Main fork

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?

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

2 / 10

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

SOC2

SAFE

ACID

HIPPA

3 / 10

3. 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

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

4 / 10

4. Which parameters sets the database default isolation level?

default_transaction_isolation

transaction_isolation_level

active_transaction_isolation

default_isolation_level

5 / 10

5. 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.

Replace procedural code with declarative one.

Use a single SQL operator

Apply explicit locks

6 / 10

6. The SQL standard specifies three isolation levels?

False

True

7 / 10

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

False

True

8 / 10

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

choose 3

Read Committed

Serializable

Read Uncommitted

Repeatable Read

9 / 10

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

True

False

10 / 10

10. 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 twice, another transaction modifies this row between these reads issue a rollback.

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.

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. CLOG contains how many bits for each transaction?

2 / 10

2. Tuples can also be referred to as columns?

False

True

3 / 10

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

Each pointer uses 4 bytes

Each pointer uses 8 bytes

Also know as the pages table of contents

stored in PGDATA/itemptr directory

4 / 10

4. Indexes values also support multi versioning with several versions of an index value existing at any point in time?

True

False

5 / 10

5. psql provides a special mode that allows you to continue a transaction after a failure?

False

True

6 / 10

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

choose 2

flashback block

page header

undo segment

free space

7 / 10

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

sequential number

checksum

xmin

backend process ID

8 / 10

8. status of a subtransaction is written into CLOG?

False

True

9 / 10

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

False

True

10 / 10

10. CLOG Pages are never cached in memory?

False

True

Your score is

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