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 purpose of the template1 database?

database used for temporary tables

regular database that you can use at your discretion

a template for all the other databases

No such database

2 / 20

2. Postgres uses a thread based process model?

False

True

3 / 20

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

False

True

4 / 20

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

False

True

5 / 20

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

False

True

6 / 20

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

False

True

7 / 20

7. What is the purpose of the visibility map?

provides the data decryption key

shows referential relationships for tables

shows a page to be vacuumed or frozen

provides an audit trail for the database

8 / 20

8. Users should not modify the template0 database

False

True

9 / 20

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

postman

postgres

init

pginit

10 / 20

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

True

False

11 / 20

11. What is the point of the pg_global tablespace?

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

stores temporary tables that are common to the whole cluster

12 / 20

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

True

False

13 / 20

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

True

False

14 / 20

14. Which fork is specific for unlogged tables?

visiblilty map

free space map

Initialization fork

Main fork

15 / 20

15. System Catalog tables begin with which prefix?

cat_

pg_

dba_

sys_

16 / 20

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

17 / 20

17. What is the purpose of the public schema?

default schema for user objects

schema used for heterogeneous replication

restricted schema for postgres internal usage only

no such schema

18 / 20

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

choose 3

tables

indexes

sequences

triggers

19 / 20

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

False

True

20 / 20

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

Directory Path

Access Path

Search Path

Schema 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 parameters sets the database default isolation level?

default_transaction_isolation

active_transaction_isolation

transaction_isolation_level

default_isolation_level

2 / 10

2. Which of the below are valid Isolations Levels?

choose 2

Serializable

Random Scatter

Rollback Read

Read Committed

3 / 10

3. 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

4 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

CREATE EXTENSTION REPEATABLE_READ;

5 / 10

5. A phantom read anomaly occurs when?

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.

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 transactions issues a commit, then a rollback to restore data to its original value

6 / 10

6. What is the default Isolation Level?

Read Committed

Serializable

Repeatable Read

Read Uncommitted

7 / 10

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

HIPPA

SOC2

ACID

SAFE

8 / 10

8. The SQL standard specifies three isolation levels?

True

False

9 / 10

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

choose 3

Read Uncommitted

Read Committed

Repeatable Read

Serializable

10 / 10

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

False

True

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

xid

xmin

xmas

xmax

2 / 10

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

pg_current_id()

pg_current_xmin_id()

pg_current_xact_id()

pg_current_commit_id()

3 / 10

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

choose 2

free space

undo segment

flashback block

page header

4 / 10

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

sequential number

xmin

checksum

backend process ID

5 / 10

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

Each pointer uses 8 bytes

Each pointer uses 4 bytes

Also know as the pages table of contents

stored in PGDATA/itemptr directory

6 / 10

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

True

False

7 / 10

7. What does an Item Pointer contain?

choose 3

tuple length

tuple status

tuple offset from the start of the page

tuple xid

8 / 10

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

True

False

9 / 10

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

False

True

10 / 10

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

True

False

Your score is

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