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 the default standard size for a fork file?

1MB

5MB

5GB

1GB

2 / 20

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

CreatePGC

StartNewPG

CreateCluster

Initialize

3 / 20

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

False

True

4 / 20

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

choose 2

pg_temp

pg_default

pg_tablespace

pg_global

5 / 20

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

6 / 20

6. Postgres by default has built in connection pooling abilities?

False

True

7 / 20

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

pg_tables

pg_system

pg_catalog

pg_class

8 / 20

8. Which of below are predefined schemas?

choose 3

information_schema

pg_schema

pg_temp

pg_toast

9 / 20

9. Which 3 databases exist directly after cluster initialization?

choose 3 options

postgres

template1

sysaux

template0

10 / 20

10. What is the purpose of wal writer?

writes WAL entries to disk

collects usage statistics for the instance.

flushes dirty pages to disk.

executes checkpoints

11 / 20

11. When PostgreSQL is running what can it be referred to as?

Choose 2 option

Instance

Postgres Server

Quorum

Aurora

12 / 20

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

True

False

13 / 20

13. System Catalog tables begin with which prefix?

dba_

sys_

cat_

pg_

14 / 20

14. Each Database has its own System Catalog?

True

False

15 / 20

15. 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

16 / 20

16. What is the purpose of the postgres database?

a template for all the other database

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

No such database

regular database that you can use at your discretion

17 / 20

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

True

False

18 / 20

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

Sam Altman

Egor Rogov

Paul Sammy

Dan Brown

19 / 20

19. Users should not modify the template0 database

False

True

20 / 20

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

Sysaux Catalog

Sysasm Catalog

System Catalog

Sys Catalog

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

Serializable

Repeatable Read

Read Committed

Read Uncommitted

2 / 10

2. Which parameters sets the database default isolation level?

transaction_isolation_level

default_transaction_isolation

default_isolation_level

active_transaction_isolation

3 / 10

3. The SQL standard specifies three isolation levels?

False

True

4 / 10

4. 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.

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

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.

5 / 10

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

choose 3

Read Uncommitted

Read Committed

Serializable

Repeatable Read

6 / 10

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

True

False

7 / 10

7. 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;

8 / 10

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

False

True

9 / 10

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

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

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

reading data direct from memory using pg_dirt

10 / 10

10. What is the default Isolation Level?

Serializable

Read Uncommitted

Read Committed

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. Rows of TOAST tables are handled in such a way that they are never update?

True

False

2 / 10

2. Page free space can often become fragmented?

True

False

3 / 10

3. Which 2 of the below represent transaction IDs used for row versioning?

xtime

xid

xmax

xmin

4 / 10

4. CLOG Pages are never cached in memory?

True

False

5 / 10

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

pg_current_commit_id()

pg_current_xact_id()

pg_current_id()

pg_current_xmin_id()

6 / 10

6. status of a subtransaction is written into CLOG?

True

False

7 / 10

7. Which of the below are true about a Pages Item Pointer?

Each pointer uses 8 bytes

Each pointer uses 4 bytes

Also know as the pages table of contents

stored in PGDATA/itemptr directory

8 / 10

8. Information about subtransactions is stored under?

PGDATA/pg_xid

PGDATA/pg_subtrans

PGDATA/subtrans

PGDATA/pg_min

9 / 10

9. Which 2 items does a Virtual XID consist of?

sequential number

backend process ID

xmin

checksum

10 / 10

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

False

True

Your score is

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