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 column in system catalogs servers as the Primary Key

obj

oid#

oid

obj#

2 / 20

2. What is the purpose of the visibility map?

provides the data decryption key

shows a page to be vacuumed or frozen

provides an audit trail for the database

shows referential relationships for tables

3 / 20

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

visiblilty map

free space map

Main fork

table map

4 / 20

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

init

pginit

postman

postgres

5 / 20

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

True

False

6 / 20

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

True

False

7 / 20

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

8 / 20

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

False

True

9 / 20

9. Which fork keeps track of available space within pages?

wal space map

free space map

vacuum space map

used space map

10 / 20

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

False

True

11 / 20

11. What is the purpose of the public schema?

default schema for user objects

no such schema

schema used for heterogeneous replication

restricted schema for postgres internal usage only

12 / 20

12. A schema can belong to more than one database?

True

False

13 / 20

13. Which fork is specific for unlogged tables?

Main fork

visiblilty map

free space map

Initialization fork

14 / 20

14. Which of below are predefined schemas?

choose 3

information_schema

pg_schema

pg_toast

pg_temp

15 / 20

15. Files are logically split into pages?

False

True

16 / 20

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

pg_class

pg_system

pg_catalog

pg_tables

17 / 20

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

BREAD

GROW

TOAST

BAKE

18 / 20

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

Search Path

Access Path

Schema Path

Directory Path

19 / 20

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

True

False

20 / 20

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

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. A phantom read anomaly occurs when?

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.

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 transactions issues a commit, then a rollback to restore data to its original value

3 / 10

3. Which parameters sets the database default isolation level?

default_transaction_isolation

active_transaction_isolation

transaction_isolation_level

default_isolation_level

4 / 10

4. 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

5 / 10

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

SAFE

SOC2

ACID

HIPPA

6 / 10

6. non-repeatable read anomaly occurs when?

A transaction reads one and the same row twice, another transaction modifies this row between these reads 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 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 issue a rollback.

7 / 10

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

choose 3

Repeatable Read

Serializable

Read Uncommitted

Read Committed

8 / 10

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

True

False

9 / 10

9. What is the default Isolation Level?

Read Committed

Repeatable Read

Read Uncommitted

Serializable

10 / 10

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

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. Which 2 items does a Virtual XID consist of?

checksum

xmin

backend process ID

sequential number

2 / 10

2. indexes do not use row versioning?

True

False

3 / 10

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

xmin

xmax

xid

xtime

4 / 10

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

False

True

5 / 10

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

True

False

6 / 10

6. What does an Item Pointer contain?

choose 3

tuple xid

tuple status

tuple length

tuple offset from the start of the page

7 / 10

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

heap XID

magic XID

temporary XID

virtual XID

8 / 10

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

Each pointer uses 8 bytes

stored in PGDATA/itemptr directory

Also know as the pages table of contents

Each pointer uses 4 bytes

9 / 10

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

False

True

10 / 10

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

INSERT

CREATE

COMMIT

DELETE

Your score is

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