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_temp

information_schema

pg_schema

pg_toast

2 / 20

2. Tablespaces are used to define physical data layout?

True

False

3 / 20

3. TOAST tables reside in a seperate schema?

False

True

4 / 20

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

True

False

5 / 20

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

choose 3

indexes

tables

triggers

sequences

6 / 20

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

Directory Path

Search Path

Access Path

Schema Path

7 / 20

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

8 / 20

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

False

True

9 / 20

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

True

False

10 / 20

10. Users should not modify the template0 database

False

True

11 / 20

11. What is the purpose of autovacuum?

Deletes old logs and traces on disk

Performs a backup of WAL logs

Rebuilds indexes with b level greater than 2

Removes stale data from tables and indexes

12 / 20

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

oid#

obj

obj#

oid

13 / 20

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

True

False

14 / 20

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

init

postman

postgres

pginit

15 / 20

15. Each Database has its own System Catalog?

False

True

16 / 20

16. What is the purpose of the postgres database?

a template for all the other database

regular database that you can use at your discretion

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

No such database

17 / 20

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

pg_tablespace

pg_tblspc

pg_symlinks

pg_tabspace

18 / 20

18. Which of below are predefined schemas?

choose 2

pg_catalog

public

postgres

system

19 / 20

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

Sam Altman

Paul Sammy

Egor Rogov

Dan Brown

20 / 20

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

False

True

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

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 once and modifies this row and commits the change.

2 / 10

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

Select more than 1 answer below:

Use a single SQL operator

Replace procedural code with declarative one.

Apply explicit locks

Issues a rollback after the commit to satisfy repeatable read.

3 / 10

3. 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 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.

4 / 10

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

False

True

5 / 10

5. 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

6 / 10

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

False

True

7 / 10

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

False

True

8 / 10

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

SOC2

HIPPA

SAFE

ACID

9 / 10

9. The SQL standard specifies three isolation levels?

True

False

10 / 10

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

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

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

COMMIT

DELETE

CREATE

INSERT

2 / 10

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

True

False

3 / 10

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

xmas

xid

xmax

xmin

4 / 10

4. Which 2 of the below represent transaction IDs used for row versioning?

xtime

xid

xmax

xmin

5 / 10

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

pagesize

pagedetect

pageheadinfo

pageinspect

6 / 10

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

pg_current_commit_id()

pg_current_id()

pg_current_xmin_id()

pg_current_xact_id()

7 / 10

7. What does an Item Pointer contain?

choose 3

tuple offset from the start of the page

tuple length

tuple xid

tuple status

8 / 10

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

True

False

9 / 10

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

True

False

10 / 10

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

False

True

Your score is

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