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 default Page size is 2k?

True

False

2 / 20

2. Postgres uses a thread based process model?

False

True

3 / 20

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

choose 2

pg_tablespace

pg_temp

pg_default

pg_global

4 / 20

4. Which 3 databases exist directly after cluster initialization?

choose 3 options

sysaux

postgres

template0

template1

5 / 20

5. Files are logically split into pages?

False

True

6 / 20

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

7 / 20

7. What is the purpose of the postgres database?

a template for all the other database

No such database

regular database that you can use at your discretion

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

8 / 20

8. What is the purpose of the visibility map?

shows a page to be vacuumed or frozen

shows referential relationships for tables

provides an audit trail for the database

provides the data decryption key

9 / 20

9. What is the default standard size for a fork file?

5MB

5GB

1MB

1GB

10 / 20

10. 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 temporary tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

11 / 20

11. Which of below are predefined schemas?

choose 2

public

system

pg_catalog

postgres

12 / 20

12. What is the name of the mechanism used to store a row bigger than a page size?

BREAD

TOAST

GROW

BAKE

13 / 20

13. What is a schema?

This is the same as a user in Postgres

The name used to refer to a super user account

Namespace that store all objects of a database

A memory area used to cache data from LRU chains

14 / 20

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

True

False

15 / 20

15. What is the purpose of autovacuum?

Removes stale data from tables and indexes

Rebuilds indexes with b level greater than 2

Deletes old logs and traces on disk

Performs a backup of WAL logs

16 / 20

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

pg_tablespace

pg_tblspc

pg_symlinks

pg_tabspace

17 / 20

17. The pg_default tablespace should never be used to create user tables?

False

True

18 / 20

18. Users should not modify the template0 database

True

False

19 / 20

19. Tablespaces can be used to segregate data based on performance needs?

True

False

20 / 20

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

init

pginit

postman

postgres

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 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.

Issues a rollback after the commit to satisfy repeatable read.

Apply explicit locks

2 / 10

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

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

3 / 10

3. What is the default Isolation Level?

Read Uncommitted

Serializable

Repeatable Read

Read Committed

4 / 10

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

True

False

5 / 10

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

SAFE

ACID

SOC2

HIPPA

6 / 10

6. Which parameters sets the database default isolation level?

active_transaction_isolation

default_transaction_isolation

transaction_isolation_level

default_isolation_level

7 / 10

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

False

True

8 / 10

8. A phantom read anomaly occurs when?

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.

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

9 / 10

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

Serializable

Read Committed

Read Uncommitted

Repeatable Read

10 / 10

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

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. Each page has a layer that usually consists of?

choose 2

flashback block

page header

undo segment

free space

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. CLOG files are stored in which directory?

PGDATA/pg_xact

PGDATA/pg_clog

PGDATA/pg_commit

PGDATA/clog

5 / 10

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

transaction log

redo log

commit log

archive log

6 / 10

6. CLOG contains how many bits for each transaction?

7 / 10

7. The page Special Space is located at the start of the page with highest address

False

True

8 / 10

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

pg_current_xact_id()

pg_current_commit_id()

pg_current_id()

pg_current_xmin_id()

9 / 10

9. Indexes values also support multi versioning with several versions of an index value existing at any point in time?

True

False

10 / 10

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

magic XID

virtual XID

heap XID

temporary XID

Your score is

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