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 single Postgres Instance can server only one database?

True

False

2 / 20

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

3 / 20

3. What is the purpose of the public schema?

restricted schema for postgres internal usage only

schema used for heterogeneous replication

no such schema

default schema for user objects

4 / 20

4. Which of below are predefined schemas?

choose 3

pg_schema

pg_toast

information_schema

pg_temp

5 / 20

5. Each Database has its own System Catalog?

True

False

6 / 20

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

Sys Catalog

Sysasm Catalog

System Catalog

Sysaux Catalog

7 / 20

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

8 / 20

8. What is another name for the postgres process?

masterprocess

postmaster

aurora

postmanager

9 / 20

9. What is the purpose of the template1 database?

a template for all the other databases

database used for temporary tables

No such database

regular database that you can use at your discretion

10 / 20

10. What is the purpose of the visibility map?

provides the data decryption key

shows a page to be vacuumed or frozen

shows referential relationships for tables

provides an audit trail for the database

11 / 20

11. Files are logically split into pages?

False

True

12 / 20

12. What is the purpose of the template0 database?

Useful for Postgres support Services to debug issues

Useful for creating development schemas

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

No such database

13 / 20

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

True

False

14 / 20

14. System Catalog tables begin with which prefix?

sys_

pg_

cat_

dba_

15 / 20

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

False

True

16 / 20

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

choose 2

pg_default

pg_temp

pg_tablespace

pg_global

17 / 20

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

init

postman

postgres

pginit

18 / 20

18. If we create a new tablespace which directory will symbolic links be created from?

pg_tabspace

pg_symlinks

pg_tablespace

pg_tblspc

19 / 20

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

undo segments (UNDO)

online redo logs (ORL)

write-ahead log (WAL)

rollback segments (RBS)

20 / 20

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

obj

oid

obj#

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 would best describe a dirty read?

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

reading data direct from memory using pg_dirt

reading the data directly from file using a text editor such as vi or notepad

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

2 / 10

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

choose 3

Repeatable Read

Serializable

Read Committed

Read Uncommitted

3 / 10

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

True

False

4 / 10

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

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

5 / 10

5. The SQL standard specifies three isolation levels?

True

False

6 / 10

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

True

False

7 / 10

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

ACID

SAFE

SOC2

HIPPA

8 / 10

8. non-repeatable read anomaly occurs when?

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.

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 and commits the change.

9 / 10

9. 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 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.

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

10 / 10

10. Which of the below are valid Isolations Levels?

choose 2

Random Scatter

Serializable

Read Committed

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

Each pointer uses 4 bytes

Each pointer uses 8 bytes

stored in PGDATA/itemptr directory

Also know as the pages table of contents

2 / 10

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

True

False

3 / 10

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

True

False

4 / 10

4. CLOG Pages are never cached in memory?

True

False

5 / 10

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

True

False

6 / 10

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

False

True

7 / 10

7. UPDATE can be regarded as which 2 separate operations?

MERGE

DELETE

INSERT

COMMIT

8 / 10

8. status of a subtransaction is written into CLOG?

True

False

9 / 10

9. indexes do not use row versioning?

False

True

10 / 10

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

clog

heap

dump

view

Your score is

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