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 a schema?

Namespace that store all objects of a database

The name used to refer to a super user account

A memory area used to cache data from LRU chains

This is the same as a user in Postgres

2 / 20

2. Which fork is specific for unlogged tables?

Main fork

Initialization fork

visiblilty map

free space map

3 / 20

3. Which of below are predefined schemas?

choose 2

pg_catalog

system

public

postgres

4 / 20

4. Which of below are predefined schemas?

choose 3

pg_schema

pg_temp

pg_toast

information_schema

5 / 20

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

False

True

6 / 20

6. TOAST tables reside in a seperate schema?

False

True

7 / 20

7. What is the purpose of the template0 database?

Useful for creating development schemas

No such database

Useful for Postgres support Services to debug issues

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

8 / 20

8. What is the purpose of the public schema?

restricted schema for postgres internal usage only

no such schema

default schema for user objects

schema used for heterogeneous replication

9 / 20

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

10 / 20

10. System Catalog tables begin with which prefix?

pg_

cat_

sys_

dba_

11 / 20

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

pg_catalog

pg_system

pg_class

pg_tables

12 / 20

12. What is the purpose of autovacuum?

Removes stale data from tables and indexes

Performs a backup of WAL logs

Deletes old logs and traces on disk

Rebuilds indexes with b level greater than 2

13 / 20

13. Tablespaces are used to define physical data layout?

True

False

14 / 20

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

True

False

15 / 20

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

True

False

16 / 20

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

Sys Catalog

System Catalog

Sysasm Catalog

Sysaux Catalog

17 / 20

17. Each Database has its own System Catalog?

False

True

18 / 20

18. What is the purpose of the postgres database?

No such database

a template for all the other database

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

regular database that you can use at your discretion

19 / 20

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

undo segments (UNDO)

online redo logs (ORL)

rollback segments (RBS)

write-ahead log (WAL)

20 / 20

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

pg_tblspc

pg_tabspace

pg_symlinks

pg_tablespace

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_isolation_level

active_transaction_isolation

default_transaction_isolation

transaction_isolation_level

2 / 10

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

True

False

3 / 10

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

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

4 / 10

4. 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 commited data altered by another session

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

reading data direct from memory using pg_dirt

5 / 10

5. Which of the below are valid Isolations Levels?

choose 2

Serializable

Read Committed

Rollback Read

Random Scatter

6 / 10

6. 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.

Use a single SQL operator

Apply explicit locks

Replace procedural code with declarative one.

7 / 10

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

SAFE

HIPPA

SOC2

ACID

8 / 10

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

Repeatable Read

Read Committed

Read Uncommitted

Serializable

9 / 10

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

False

True

10 / 10

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

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. a transaction containing a savepoint is will still be considered as only a single transaction?

False

True

2 / 10

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

False

True

3 / 10

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

False

True

4 / 10

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

True

False

5 / 10

5. CLOG Pages are never cached in memory?

False

True

6 / 10

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

MERGE

INSERT

DELETE

COMMIT

7 / 10

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

choose 2

flashback block

undo segment

page header

free space

8 / 10

8. CLOG contains how many bits for each transaction?

9 / 10

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

pg_current_xact_id()

pg_current_commit_id()

pg_current_xmin_id()

pg_current_id()

10 / 10

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

True

False

Your score is

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