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. TOAST tables reside in a seperate schema?

False

True

2 / 20

2. What is the point of the pg_global tablespace?

stores system catalog objects that are common to the whole cluster

stores temporary tables that are common to the whole cluster

stores WAL logs used for global replication

stores user tables that are common to the whole cluster

3 / 20

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

Sam Altman

Paul Sammy

Dan Brown

Egor Rogov

4 / 20

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

False

True

5 / 20

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

True

False

6 / 20

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

7 / 20

7. Files are logically split into pages?

False

True

8 / 20

8. pg_catalog schema is used to store system catalog tables?

True

False

9 / 20

9. The default Page size is 2k?

False

True

10 / 20

10. Which fork is specific for unlogged tables?

Main fork

visiblilty map

free space map

Initialization fork

11 / 20

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

undo segments (UNDO)

rollback segments (RBS)

write-ahead log (WAL)

online redo logs (ORL)

12 / 20

12. System Catalog tables begin with which prefix?

dba_

sys_

cat_

pg_

13 / 20

13. What is the purpose of the postgres database?

regular database that you can use at your discretion

No such database

a template for all the other database

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

14 / 20

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

True

False

15 / 20

15. Each Database has its own System Catalog?

True

False

16 / 20

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

Directory Path

Schema Path

Search Path

Access Path

17 / 20

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

False

True

18 / 20

18. What is the name of the system catalog table for relations?

pg_catalog

pg_system

pg_tables

pg_class

19 / 20

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

PGTIPS

PGBASE

PGDATA

PGCORE

20 / 20

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

postman

postgres

pginit

init

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

SAFE

ACID

SOC2

HIPPA

2 / 10

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

False

True

3 / 10

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

True

False

4 / 10

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

True

False

5 / 10

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

Select more than 1 answer below:

Apply explicit locks

Issues a rollback after the commit to satisfy repeatable read.

Use a single SQL operator

Replace procedural code with declarative one.

6 / 10

6. 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 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.

7 / 10

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

choose 3

Read Uncommitted

Serializable

Read Committed

Repeatable Read

8 / 10

8. A phantom read anomaly occurs when?

A transactions inserts a null value into a not null columns and commits

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 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.

9 / 10

9. What is the default Isolation Level?

Read Committed

Serializable

Repeatable Read

Read Uncommitted

10 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=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. 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()

2 / 10

2. CLOG files are stored in which directory?

PGDATA/pg_clog

PGDATA/pg_xact

PGDATA/pg_commit

PGDATA/clog

3 / 10

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

True

False

4 / 10

4. CLOG contains how many bits for each transaction?

5 / 10

5. UPDATE can be regarded as which 2 separate operations?

DELETE

COMMIT

MERGE

INSERT

6 / 10

6. What does an Item Pointer contain?

choose 3

tuple offset from the start of the page

tuple xid

tuple length

tuple status

7 / 10

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

True

False

8 / 10

8. CLOG Pages are never cached in memory?

False

True

9 / 10

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

xmas

xid

xmax

xmin

10 / 10

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

choose 2

flashback block

free space

page header

undo segment

Your score is

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