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. The information_schema schema provides information on Postgres release notes?

True

False

2 / 20

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

True

False

3 / 20

3. What is the purpose of the public schema?

no such schema

schema used for heterogeneous replication

default schema for user objects

restricted schema for postgres internal usage only

4 / 20

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

True

False

5 / 20

5. What is the purpose of the template1 database?

a template for all the other databases

regular database that you can use at your discretion

database used for temporary tables

No such database

6 / 20

6. 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

7 / 20

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

pg_tablespace

pg_tblspc

pg_tabspace

pg_symlinks

8 / 20

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

False

True

9 / 20

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

True

False

10 / 20

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

choose 3

indexes

tables

sequences

triggers

11 / 20

11. Which fork contains the actual table data?

free space map

table map

visiblilty map

Main fork

12 / 20

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

Paul Sammy

Sam Altman

Egor Rogov

Dan Brown

13 / 20

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

False

True

14 / 20

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

Access Path

Search Path

Directory Path

Schema Path

15 / 20

15. What is the purpose of autovacuum?

Deletes old logs and traces on disk

Performs a backup of WAL logs

Removes stale data from tables and indexes

Rebuilds indexes with b level greater than 2

16 / 20

16. Which of below are predefined schemas?

choose 3

pg_schema

information_schema

pg_toast

pg_temp

17 / 20

17. Files are logically split into pages?

True

False

18 / 20

18. The default Page size is 2k?

False

True

19 / 20

19. What command is used to create the Postgres cluster?

StartNewPG

CreatePGC

CreateCluster

Initialize

20 / 20

20. Each Database has its own System Catalog?

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

False

True

2 / 10

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

Repeatable Read

Read Committed

Read Uncommitted

Serializable

3 / 10

3. 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 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 and modifies this row and commits the change.

4 / 10

4. What is the default Isolation Level?

Read Uncommitted

Read Committed

Serializable

Repeatable Read

5 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

6 / 10

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

choose 3

Read Uncommitted

Repeatable Read

Serializable

Read Committed

7 / 10

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

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

a session being able to see commited data altered by another session

reading data direct from memory using pg_dirt

8 / 10

8. 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

Apply explicit locks

Issues a rollback after the commit to satisfy repeatable read.

Replace procedural code with declarative one.

9 / 10

9. Which of the below are valid Isolations Levels?

choose 2

Read Committed

Rollback Read

Serializable

Random Scatter

10 / 10

10. 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.

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. Page free space can often become fragmented?

False

True

2 / 10

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

False

True

3 / 10

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

False

True

4 / 10

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

True

False

5 / 10

5. When a transaction is committed Postgres uses a special <replace with answer> structure?

transaction log

commit log

archive log

redo log

6 / 10

6. CLOG Pages are never cached in memory?

False

True

7 / 10

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

False

True

8 / 10

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

pg_current_commit_id()

pg_current_id()

pg_current_xact_id()

pg_current_xmin_id()

9 / 10

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

MERGE

DELETE

INSERT

COMMIT

10 / 10

10. status of a subtransaction is written into CLOG?

True

False

Your score is

Cookie	Duration	Description
cookielawinfo-checkbox-analytics	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Analytics".
cookielawinfo-checkbox-functional	11 months	The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional".
cookielawinfo-checkbox-necessary	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookies is used to store the user consent for the cookies in the category "Necessary".
cookielawinfo-checkbox-others	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Other.
cookielawinfo-checkbox-performance	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Performance".
viewed_cookie_policy	11 months	The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. It does not store any personal data.