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. pg_catalog schema is used to store system catalog tables?

True

False

2 / 20

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

False

True

3 / 20

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

PGTIPS

PGDATA

PGCORE

PGBASE

4 / 20

4. Which of below are predefined schemas?

choose 2

postgres

public

system

pg_catalog

5 / 20

5. What command is used to create the Postgres cluster?

CreatePGC

StartNewPG

Initialize

CreateCluster

6 / 20

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

True

False

7 / 20

7. What is the purpose of the public schema?

default schema for user objects

schema used for heterogeneous replication

no such schema

restricted schema for postgres internal usage only

8 / 20

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

Access Path

Directory Path

Search Path

Schema Path

9 / 20

9. What is the purpose of the template0 database?

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

No such database

Useful for Postgres support Services to debug issues

Useful for creating development schemas

10 / 20

10. Which fork is specific for unlogged tables?

Main fork

visiblilty map

Initialization fork

free space map

11 / 20

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

rollback segments (RBS)

online redo logs (ORL)

write-ahead log (WAL)

undo segments (UNDO)

12 / 20

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

False

True

13 / 20

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

Choose 2 option

Aurora

Postgres Server

Quorum

Instance

14 / 20

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

postman

init

pginit

postgres

15 / 20

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

16 / 20

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

True

False

17 / 20

17. What is a schema?

Namespace that store all objects of a database

A memory area used to cache data from LRU chains

This is the same as a user in Postgres

The name used to refer to a super user account

18 / 20

18. The pg_default tablespace should never be used to create user tables?

False

True

19 / 20

19. What is the point of the pg_global tablespace?

stores WAL logs used for global replication

stores temporary tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

stores user tables that are common to the whole cluster

20 / 20

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

free space map

table map

Main fork

visiblilty map

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

False

True

2 / 10

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

False

True

3 / 10

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

True

False

4 / 10

4. The SQL standard specifies three isolation levels?

False

True

5 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

6 / 10

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

Select more than 1 answer below:

Replace procedural code with declarative one.

Use a single SQL operator

Apply explicit locks

Issues a rollback after the commit to satisfy repeatable read.

7 / 10

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

False

True

8 / 10

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

True

False

9 / 10

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

ACID

SAFE

SOC2

HIPPA

10 / 10

10. non-repeatable read anomaly occurs when?

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.

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.

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

True

False

2 / 10

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

INSERT

CREATE

COMMIT

DELETE

3 / 10

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

False

True

4 / 10

4. indexes do not use row versioning?

True

False

5 / 10

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

pg_current_xmin_id()

pg_current_xact_id()

pg_current_id()

pg_current_commit_id()

6 / 10

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

xmas

xid

xmax

xmin

7 / 10

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

False

True

8 / 10

8. Which 2 of the below represent transaction IDs used for row versioning?

xtime

xmin

xid

xmax

9 / 10

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

COMMIT

MERGE

DELETE

INSERT

10 / 10

10. Information about subtransactions is stored under?

PGDATA/pg_subtrans

PGDATA/subtrans

PGDATA/pg_min

PGDATA/pg_xid

Your score is

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