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 purpose of the template0 database?

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

Useful for Postgres support Services to debug issues

Useful for creating development schemas

No such database

2 / 20

2. Which of below are predefined schemas?

choose 2

pg_catalog

public

system

postgres

3 / 20

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

Directory Path

Search Path

Access Path

Schema Path

4 / 20

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

False

True

5 / 20

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

False

True

6 / 20

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

init

postgres

pginit

postman

7 / 20

7. Which 3 databases exist directly after cluster initialization?

choose 3 options

postgres

template0

sysaux

template1

8 / 20

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

True

False

9 / 20

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

Main fork

table map

free space map

visiblilty map

10 / 20

10. The default Page size is 2k?

True

False

11 / 20

11. What is the name of the directory that contains the files related to the Postgres cluster?

PGBASE

PGDATA

PGTIPS

PGCORE

12 / 20

12. Tablespaces are used to define physical data layout?

True

False

13 / 20

13. Files are logically split into pages?

False

True

14 / 20

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

pg_system

pg_tables

pg_catalog

pg_class

15 / 20

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

Choose 2 option

Instance

Aurora

Quorum

Postgres Server

16 / 20

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

False

True

17 / 20

17. What is the purpose of the visibility map?

provides the data decryption key

provides an audit trail for the database

shows referential relationships for tables

shows a page to be vacuumed or frozen

18 / 20

18. What is another name for the postgres process?

postmanager

aurora

masterprocess

postmaster

19 / 20

19. What is the purpose of wal writer?

writes WAL entries to disk

collects usage statistics for the instance.

executes checkpoints

flushes dirty pages to disk.

20 / 20

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

write-ahead log (WAL)

online redo logs (ORL)

undo segments (UNDO)

rollback segments (RBS)

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

True

False

2 / 10

2. Which of the below are valid Isolations Levels?

choose 2

Random Scatter

Read Committed

Rollback Read

Serializable

3 / 10

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

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.

4 / 10

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

False

True

5 / 10

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

Read Uncommitted

Repeatable Read

Read Committed

Serializable

6 / 10

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

choose 3

Read Committed

Repeatable Read

Read Uncommitted

Serializable

7 / 10

7. non-repeatable read anomaly occurs when?

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.

A transaction reads one and the same row once and modifies this row and commits the change.

8 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

9 / 10

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

False

True

10 / 10

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

HIPPA

ACID

SOC2

SAFE

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. Tuples can also be referred to as columns?

False

True

2 / 10

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

heap XID

magic XID

temporary XID

virtual XID

3 / 10

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

True

False

4 / 10

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

True

False

5 / 10

5. Postgres table physical data files are always cross compatible across platforms?

True

False

6 / 10

6. Page header sizes can be easily displayed using the <choose from answers> extension

pagedetect

pageheadinfo

pageinspect

pagesize

7 / 10

7. What does an Item Pointer contain?

choose 3

tuple length

tuple offset from the start of the page

tuple xid

tuple status

8 / 10

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

pg_current_xact_id()

pg_current_id()

pg_current_xmin_id()

pg_current_commit_id()

9 / 10

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

COMMIT

CREATE

INSERT

DELETE

10 / 10

10. To identify different versions of one and the same row, PostgreSQL marks each of them with which two value?

xmax

xmas

xmin

xid

Your score is

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