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 is a schema?

Namespace that store all objects of a database

The name used to refer to a super user account

This is the same as a user in Postgres

A memory area used to cache data from LRU chains

2 / 20

2. Which of below are predefined schemas?

choose 3

information_schema

pg_temp

pg_toast

pg_schema

3 / 20

3. What is the purpose of the public schema?

no such schema

restricted schema for postgres internal usage only

default schema for user objects

schema used for heterogeneous replication

4 / 20

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

obj#

oid

oid#

obj

5 / 20

5. Each Database has its own System Catalog?

True

False

6 / 20

6. Postgres by default has built in connection pooling abilities?

True

False

7 / 20

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

PGBASE

PGTIPS

PGDATA

PGCORE

8 / 20

8. Postgres uses a thread based process model?

False

True

9 / 20

9. Which of below are predefined schemas?

choose 2

pg_catalog

system

public

postgres

10 / 20

10. Which 3 databases exist directly after cluster initialization?

choose 3 options

template1

postgres

template0

sysaux

11 / 20

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

Choose 2 option

Postgres Server

Quorum

Instance

Aurora

12 / 20

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

pginit

postgres

postman

init

13 / 20

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

undo segments (UNDO)

rollback segments (RBS)

write-ahead log (WAL)

online redo logs (ORL)

14 / 20

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

visiblilty map

free space map

Main fork

table map

15 / 20

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

BAKE

TOAST

GROW

BREAD

16 / 20

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

free space map

vacuum space map

used space map

wal space map

17 / 20

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

pg_system

pg_catalog

pg_class

pg_tables

18 / 20

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

True

False

19 / 20

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

False

True

20 / 20

20. A single Postgres Instance can server only one database?

True

False

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

True

False

2 / 10

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

choose 3

Read Uncommitted

Serializable

Read Committed

Repeatable Read

3 / 10

3. Which parameters sets the database default isolation level?

transaction_isolation_level

default_isolation_level

default_transaction_isolation

active_transaction_isolation

4 / 10

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

Read Uncommitted

Repeatable Read

Serializable

Read Committed

5 / 10

5. What is the default Isolation Level?

Repeatable Read

Serializable

Read Committed

Read Uncommitted

6 / 10

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

False

True

7 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

8 / 10

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

False

True

9 / 10

9. 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 adds some other rows satisfying this condition and commits.

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

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 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.

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?

Also know as the pages table of contents

stored in PGDATA/itemptr directory

Each pointer uses 4 bytes

Each pointer uses 8 bytes

2 / 10

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

True

False

3 / 10

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

True

False

4 / 10

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

True

False

5 / 10

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

COMMIT

INSERT

MERGE

DELETE

6 / 10

6. status of a subtransaction is written into CLOG?

True

False

7 / 10

7. Each page has a layer that usually consists of?

choose 2

undo segment

page header

flashback block

free space

8 / 10

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

True

False

9 / 10

9. If a transaction is read only which kind of Transaction ID is it allocated?

magic XID

heap XID

virtual XID

temporary XID

10 / 10

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

True

False

Your score is

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