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. Files are logically split into pages?

False

True

2 / 20

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

Main fork

free space map

visiblilty map

table map

3 / 20

3. What is the purpose of the visibility map?

provides the data decryption key

shows referential relationships for tables

provides an audit trail for the database

shows a page to be vacuumed or frozen

4 / 20

4. Which fork is specific for unlogged tables?

Main fork

visiblilty map

Initialization fork

free space map

5 / 20

5. It is the postmasters job to listener for incoming connections?

True

False

6 / 20

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

True

False

7 / 20

7. Each tablespaces can only be assigned for use by one database

False

True

8 / 20

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

BREAD

BAKE

GROW

TOAST

9 / 20

9. TOAST tables reside in a seperate schema?

True

False

10 / 20

10. Each Database has its own System Catalog?

True

False

11 / 20

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

12 / 20

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

wal space map

used space map

free space map

vacuum space map

13 / 20

13. What is a schema?

This is the same as a user in Postgres

A memory area used to cache data from LRU chains

The name used to refer to a super user account

Namespace that store all objects of a database

14 / 20

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

False

True

15 / 20

15. What is the purpose of autovacuum?

Rebuilds indexes with b level greater than 2

Removes stale data from tables and indexes

Deletes old logs and traces on disk

Performs a backup of WAL logs

16 / 20

16. Which 3 databases exist directly after cluster initialization?

choose 3 options

template1

template0

postgres

sysaux

17 / 20

17. What is the purpose of the template1 database?

regular database that you can use at your discretion

database used for temporary tables

a template for all the other databases

No such database

18 / 20

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

True

False

19 / 20

19. Which of below are predefined schemas?

choose 3

information_schema

pg_toast

pg_schema

pg_temp

20 / 20

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

obj

obj#

oid

oid#

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 of the below are valid Isolations Levels?

choose 2

Read Committed

Random Scatter

Serializable

Rollback Read

2 / 10

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

False

True

3 / 10

3. 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.

4 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

5 / 10

5. Which parameters sets the database default isolation level?

default_isolation_level

active_transaction_isolation

default_transaction_isolation

transaction_isolation_level

6 / 10

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

True

False

7 / 10

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

True

False

8 / 10

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

SOC2

SAFE

HIPPA

ACID

9 / 10

9. What is the default Isolation Level?

Read Committed

Serializable

Repeatable Read

Read Uncommitted

10 / 10

10. 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 twice, another transaction modifies this row between these reads issue a rollback.

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

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

False

True

2 / 10

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

False

True

3 / 10

3. indexes do not use row versioning?

False

True

4 / 10

4. If a transaction aborts, all page changes are reverted(rolled back) in place?

False

True

5 / 10

5. Information about subtransactions is stored under?

PGDATA/subtrans

PGDATA/pg_min

PGDATA/pg_xid

PGDATA/pg_subtrans

6 / 10

6. In Postgres, tables are often referred to as which of the below?

clog

dump

view

heap

7 / 10

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

False

True

8 / 10

8. The page header stores checksum and the sizes of the other parts of the page?

True

False

9 / 10

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

xid

xmin

xtime

xmax

10 / 10

10. CLOG Pages are never cached in memory?

True

False

Your score is

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