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. Users should not modify the template0 database

False

True

2 / 20

2. Which of below are predefined schemas?

choose 2

system

public

pg_catalog

postgres

3 / 20

3. Which of below are predefined schemas?

choose 3

pg_schema

pg_temp

pg_toast

information_schema

4 / 20

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

True

False

5 / 20

5. What is another name for the postgres process?

masterprocess

postmaster

aurora

postmanager

6 / 20

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

write-ahead log (WAL)

rollback segments (RBS)

undo segments (UNDO)

online redo logs (ORL)

7 / 20

7. pg_catalog schema is used to store system catalog tables?

False

True

8 / 20

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

Directory Path

Search Path

Access Path

Schema Path

9 / 20

9. Tablespaces are used to define physical data layout?

True

False

10 / 20

10. What is the purpose of the visibility map?

shows a page to be vacuumed or frozen

provides the data decryption key

shows referential relationships for tables

provides an audit trail for the database

11 / 20

11. TOAST tables reside in a seperate schema?

True

False

12 / 20

12. What is the point of the pg_global tablespace?

stores system catalog objects that are common to the whole cluster

stores temporary tables that are common to the whole cluster

stores WAL logs used for global replication

stores user tables that are common to the whole cluster

13 / 20

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

choose 2

pg_tablespace

pg_default

pg_temp

pg_global

14 / 20

14. Postgres uses a thread based process model?

True

False

15 / 20

15. What is the purpose of the postgres database?

regular database that you can use at your discretion

a template for all the other database

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

No such database

16 / 20

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

vacuum space map

free space map

wal space map

used space map

17 / 20

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

Main fork

visiblilty map

free space map

table map

18 / 20

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

pg_class

pg_tables

pg_catalog

pg_system

19 / 20

19. What is the purpose of the public schema?

no such schema

default schema for user objects

schema used for heterogeneous replication

restricted schema for postgres internal usage only

20 / 20

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

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. The SQL standard specifies three isolation levels?

False

True

2 / 10

2. 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;

3 / 10

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

False

True

4 / 10

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

reading data direct from memory using pg_dirt

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

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

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

5 / 10

5. Which of the below are valid Isolations Levels?

choose 2

Rollback Read

Read Committed

Serializable

Random Scatter

6 / 10

6. 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 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 issue a rollback.

7 / 10

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

False

True

8 / 10

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

choose 3

Serializable

Read Uncommitted

Repeatable Read

Read Committed

9 / 10

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

HIPPA

SOC2

SAFE

ACID

10 / 10

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

True

False

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?

True

False

2 / 10

2. Information about subtransactions is stored under?

PGDATA/pg_min

PGDATA/subtrans

PGDATA/pg_subtrans

PGDATA/pg_xid

3 / 10

3. CLOG files are stored in which directory?

PGDATA/clog

PGDATA/pg_clog

PGDATA/pg_xact

PGDATA/pg_commit

4 / 10

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

DELETE

CREATE

INSERT

COMMIT

5 / 10

5. status of a subtransaction is written into CLOG?

True

False

6 / 10

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

stored in PGDATA/itemptr directory

Each pointer uses 4 bytes

Also know as the pages table of contents

Each pointer uses 8 bytes

7 / 10

7. Which 2 items does a Virtual XID consist of?

backend process ID

sequential number

xmin

checksum

8 / 10

8. What does an Item Pointer contain?

choose 3

tuple offset from the start of the page

tuple status

tuple xid

tuple length

9 / 10

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

False

True

10 / 10

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

pageinspect

pagedetect

pageheadinfo

pagesize

Your score is

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