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 fork keeps track of available space within pages?

used space map

free space map

wal space map

vacuum space map

2 / 20

2. TOAST tables reside in a seperate schema?

False

True

3 / 20

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

False

True

4 / 20

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

True

False

5 / 20

5. What is the purpose of the postgres database?

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

No such database

a template for all the other database

regular database that you can use at your discretion

6 / 20

6. What is the purpose of the visibility map?

shows referential relationships for tables

provides an audit trail for the database

provides the data decryption key

shows a page to be vacuumed or frozen

7 / 20

7. What is the purpose of the template1 database?

No such database

regular database that you can use at your discretion

database used for temporary tables

a template for all the other databases

8 / 20

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

Schema Path

Access Path

Search Path

Directory Path

9 / 20

9. What is the name of the catalog that stores metadata for all cluster objects?

Sysasm Catalog

Sysaux Catalog

Sys Catalog

System Catalog

10 / 20

10. What is the purpose of the template0 database?

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

Useful for creating development schemas

Useful for Postgres support Services to debug issues

No such database

11 / 20

11. The information_schema schema provides information on Postgres release notes?

False

True

12 / 20

12. Tablespaces are used to define physical data layout?

False

True

13 / 20

13. Postgres uses a thread based process model?

True

False

14 / 20

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

True

False

15 / 20

15. What is a schema?

A memory area used to cache data from LRU chains

Namespace that store all objects of a database

This is the same as a user in Postgres

The name used to refer to a super user account

16 / 20

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

17 / 20

17. What is the name of the 2 default tablespaces created after initialization?

choose 2

pg_temp

pg_default

pg_tablespace

pg_global

18 / 20

18. Files are logically split into pages?

True

False

19 / 20

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

write-ahead log (WAL)

undo segments (UNDO)

online redo logs (ORL)

rollback segments (RBS)

20 / 20

20. Users should not modify the template0 database

True

False

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. non-repeatable read anomaly occurs when?

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.

A transaction reads one and the same row twice, another transaction modifies this row between these reads and commits the change.

3 / 10

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

True

False

4 / 10

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

True

False

5 / 10

5. 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;

6 / 10

6. What is the default Isolation Level?

Repeatable Read

Serializable

Read Committed

Read Uncommitted

7 / 10

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

True

False

8 / 10

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

False

True

9 / 10

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

choose 3

Read Uncommitted

Repeatable Read

Serializable

Read Committed

10 / 10

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

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

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

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. In Postgres, tables are often referred to as which of the below?

clog

heap

dump

view

3 / 10

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

INSERT

CREATE

COMMIT

DELETE

4 / 10

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

xmax

xmas

xmin

xid

5 / 10

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

pg_current_commit_id()

pg_current_xmin_id()

pg_current_xact_id()

pg_current_id()

6 / 10

6. status of a subtransaction is written into CLOG?

True

False

7 / 10

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

redo log

archive log

transaction log

commit log

8 / 10

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

pageinspect

pageheadinfo

pagedetect

pagesize

9 / 10

9. If a transaction is read only which kind of Transaction ID is it allocated?

temporary XID

magic XID

heap XID

virtual XID

10 / 10

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

False

True

Your score is

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