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

True

False

2 / 20

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

1MB

5GB

5MB

1GB

3 / 20

3. Each Database has its own System Catalog?

False

True

4 / 20

4. What is the purpose of wal writer?

writes WAL entries to disk

flushes dirty pages to disk.

collects usage statistics for the instance.

executes checkpoints

5 / 20

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

init

postman

postgres

pginit

6 / 20

6. What is the purpose of the postgres database?

regular database that you can use at your discretion

No such database

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

a template for all the other database

7 / 20

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

Search Path

Directory Path

Access Path

Schema Path

8 / 20

8. What is the purpose of the template1 database?

regular database that you can use at your discretion

No such database

database used for temporary tables

a template for all the other databases

9 / 20

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

True

False

10 / 20

10. A single Postgres Instance can server only one database?

False

True

11 / 20

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

Initialize

CreatePGC

StartNewPG

CreateCluster

12 / 20

12. What column in system catalogs servers as the Primary Key

oid

obj#

obj

oid#

13 / 20

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

Sysasm Catalog

System Catalog

Sysaux Catalog

Sys Catalog

14 / 20

14. What is a schema?

This is the same as a user in Postgres

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

15 / 20

15. Which of below are predefined schemas?

choose 2

public

pg_catalog

system

postgres

16 / 20

16. What is another name for the postgres process?

postmanager

aurora

postmaster

masterprocess

17 / 20

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

True

False

18 / 20

18. What 3 files/forks as a minimum make up a table on disk?

free space map

visiblilty map

Main fork

table map

19 / 20

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

choose 3

indexes

tables

sequences

triggers

20 / 20

20. What is the point of the pg_global tablespace?

stores temporary 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 user tables that are common to the whole cluster

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

ACID

SOC2

SAFE

HIPPA

2 / 10

2. Which parameters sets the database default isolation level?

active_transaction_isolation

default_isolation_level

transaction_isolation_level

default_transaction_isolation

3 / 10

3. What is the default Isolation Level?

Read Committed

Serializable

Repeatable Read

Read Uncommitted

4 / 10

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

True

False

5 / 10

5. A phantom read anomaly occurs when?

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 also queries this same data.

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 adds some other rows satisfying this condition and commits.

6 / 10

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

choose 3

Read Committed

Repeatable Read

Serializable

Read Uncommitted

7 / 10

7. non-repeatable read anomaly occurs when?

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 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.

8 / 10

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

True

False

9 / 10

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

True

False

10 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL 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. at any one time Postgres can have several versions of a row?

False

True

2 / 10

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

CREATE

INSERT

COMMIT

DELETE

3 / 10

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

False

True

4 / 10

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

Also know as the pages table of contents

Each pointer uses 4 bytes

stored in PGDATA/itemptr directory

Each pointer uses 8 bytes

5 / 10

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

xmin

backend process ID

checksum

sequential number

6 / 10

6. status of a subtransaction is written into CLOG?

False

True

7 / 10

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

False

True

8 / 10

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

False

True

9 / 10

9. Page free space can often become fragmented?

True

False

10 / 10

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

temporary XID

virtual XID

magic XID

heap XID

Your score is

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