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. Which of below are predefined schemas?

choose 2

postgres

pg_catalog

system

public

2 / 20

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

True

False

3 / 20

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

vacuum space map

used space map

wal space map

free space map

4 / 20

4. What is the purpose of the public schema?

schema used for heterogeneous replication

restricted schema for postgres internal usage only

no such schema

default schema for user objects

5 / 20

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

True

False

6 / 20

6. 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 creating development schemas

Useful for Postgres support Services to debug issues

No such database

7 / 20

7. System Catalog tables begin with which prefix?

cat_

dba_

sys_

pg_

8 / 20

8. The default Page size is 2k?

False

True

9 / 20

9. Which of below are predefined schemas?

choose 3

pg_temp

information_schema

pg_toast

pg_schema

10 / 20

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

True

False

11 / 20

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

pginit

postgres

postman

init

12 / 20

12. Postgres uses a thread based process model?

True

False

13 / 20

13. What is the purpose of the postgres database?

regular database that you can use at your discretion

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

No such database

a template for all the other database

14 / 20

14. What is the purpose of wal writer?

collects usage statistics for the instance.

executes checkpoints

flushes dirty pages to disk.

writes WAL entries to disk

15 / 20

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

TOAST

BAKE

BREAD

GROW

16 / 20

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

Choose 2 option

Instance

Aurora

Quorum

Postgres Server

17 / 20

17. What is another name for the postgres process?

postmaster

masterprocess

postmanager

aurora

18 / 20

18. Users should not modify the template0 database

False

True

19 / 20

19. Which fork contains the actual table data?

visiblilty map

free space map

Main fork

table map

20 / 20

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

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. What is the default Isolation Level?

Read Uncommitted

Repeatable Read

Serializable

Read Committed

2 / 10

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

True

False

3 / 10

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

False

True

4 / 10

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

False

True

5 / 10

5. 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

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

6 / 10

6. A phantom read anomaly occurs when?

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

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.

7 / 10

7. The SQL standard specifies three isolation levels?

False

True

8 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

9 / 10

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

False

True

10 / 10

10. Which parameters sets the database default isolation level?

default_transaction_isolation

active_transaction_isolation

default_isolation_level

transaction_isolation_level

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

True

False

2 / 10

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

False

True

3 / 10

3. When a transaction is committed Postgres uses a special <replace with answer> structure?

archive log

commit log

transaction log

redo log

4 / 10

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

False

True

5 / 10

5. at any one time Postgres can have several versions of a row?

True

False

6 / 10

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

stored in PGDATA/itemptr directory

Also know as the pages table of contents

Each pointer uses 8 bytes

Each pointer uses 4 bytes

7 / 10

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

pg_current_commit_id()

pg_current_xact_id()

pg_current_xmin_id()

pg_current_id()

8 / 10

8. Page free space can often become fragmented?

True

False

9 / 10

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

False

True

10 / 10

10. Tuples can also be referred to as columns?

True

False

Your score is

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