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 command is used to create the Postgres cluster?

StartNewPG

Initialize

CreateCluster

CreatePGC

2 / 20

2. What is the purpose of the visibility map?

provides an audit trail for the database

shows referential relationships for tables

provides the data decryption key

shows a page to be vacuumed or frozen

3 / 20

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

4 / 20

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

PGTIPS

PGBASE

PGDATA

PGCORE

5 / 20

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

6 / 20

6. Which 3 databases exist directly after cluster initialization?

choose 3 options

template0

sysaux

postgres

template1

7 / 20

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

choose 3

tables

sequences

triggers

indexes

8 / 20

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

False

True

9 / 20

9. Which of below are predefined schemas?

choose 3

pg_temp

pg_schema

pg_toast

information_schema

10 / 20

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

5GB

1GB

5MB

1MB

11 / 20

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

True

False

12 / 20

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

False

True

13 / 20

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

postgres

pginit

init

postman

14 / 20

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

pg_system

pg_catalog

pg_class

pg_tables

15 / 20

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

free space map

wal space map

used space map

vacuum space map

16 / 20

16. Postgres uses a thread based process model?

True

False

17 / 20

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

False

True

18 / 20

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

False

True

19 / 20

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

True

False

20 / 20

20. The default Page size is 2k?

False

True

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

Read Uncommitted

Read Committed

Repeatable Read

Serializable

2 / 10

2. Which of the below would best describe a dirty read?

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

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

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

reading data direct from memory using pg_dirt

3 / 10

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

True

False

4 / 10

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

False

True

5 / 10

5. What are some of database features we can use to avoid a non repeatable read?

Select more than 1 answer below:

Apply explicit locks

Replace procedural code with declarative one.

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

6 / 10

6. The SQL standard specifies three isolation levels?

False

True

7 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

8 / 10

8. Which of the below are valid Isolations Levels?

choose 2

Serializable

Rollback Read

Random Scatter

Read Committed

9 / 10

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

True

False

10 / 10

10. 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 twice, 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, another transaction modifies this row between these reads 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. When a transaction is committed Postgres uses a special <replace with answer> structure?

archive log

commit log

transaction log

redo log

2 / 10

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

False

True

3 / 10

3. Information about subtransactions is stored under?

PGDATA/pg_subtrans

PGDATA/pg_min

PGDATA/pg_xid

PGDATA/subtrans

4 / 10

4. CLOG files are stored in which directory?

PGDATA/pg_clog

PGDATA/pg_xact

PGDATA/pg_commit

PGDATA/clog

5 / 10

5. virtual IDs exist only in PGDATA/pg_vxid when not cached?

False

True

6 / 10

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

clog

heap

dump

view

7 / 10

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

False

True

8 / 10

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

xmax

xmin

xid

xmas

9 / 10

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

DELETE

INSERT

CREATE

COMMIT

10 / 10

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

True

False

Your score is

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