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

True

False

2 / 20

2. Which of below are predefined schemas?

choose 2

public

postgres

system

pg_catalog

3 / 20

3. What is a schema?

Namespace that store all objects of a database

A memory area used to cache data from LRU chains

The name used to refer to a super user account

This is the same as a user in Postgres

4 / 20

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

False

True

5 / 20

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

6 / 20

6. Postgres uses a thread based process model?

True

False

7 / 20

7. What is the purpose of the public schema?

no such schema

default schema for user objects

restricted schema for postgres internal usage only

schema used for heterogeneous replication

8 / 20

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

False

True

9 / 20

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

GROW

BREAD

TOAST

BAKE

10 / 20

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

pg_class

pg_catalog

pg_tables

pg_system

11 / 20

11. TOAST tables reside in a seperate schema?

True

False

12 / 20

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

True

False

13 / 20

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

5GB

5MB

1GB

1MB

14 / 20

14. Which 3 databases exist directly after cluster initialization?

choose 3 options

template1

sysaux

template0

postgres

15 / 20

15. Postgres server spawns a new backend session for each connection?

False

True

16 / 20

16. Which fork contains the actual table data?

visiblilty map

table map

free space map

Main fork

17 / 20

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

rollback segments (RBS)

undo segments (UNDO)

online redo logs (ORL)

write-ahead log (WAL)

18 / 20

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

Choose 2 option

Instance

Postgres Server

Aurora

Quorum

19 / 20

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

True

False

20 / 20

20. Which of below are predefined schemas?

choose 3

pg_schema

pg_temp

information_schema

pg_toast

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?

False

True

2 / 10

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

SOC2

SAFE

ACID

HIPPA

3 / 10

3. What is the default Isolation Level?

Repeatable Read

Serializable

Read Committed

Read Uncommitted

4 / 10

4. Which parameters sets the database default isolation level?

default_isolation_level

active_transaction_isolation

default_transaction_isolation

transaction_isolation_level

5 / 10

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

Select more than 1 answer below:

Use a single SQL operator

Apply explicit locks

Replace procedural code with declarative one.

Issues a rollback after the commit to satisfy repeatable read.

6 / 10

6. A phantom read anomaly occurs when?

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.

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 also queries this same data.

The same transactions issues a commit, then a rollback to restore data to its original value

7 / 10

7. The SQL standard specifies three isolation levels?

True

False

8 / 10

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

False

True

9 / 10

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

False

True

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 issue a rollback.

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.

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?

False

True

2 / 10

2. CLOG files are stored in which directory?

PGDATA/pg_commit

PGDATA/pg_xact

PGDATA/clog

PGDATA/pg_clog

3 / 10

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

pg_current_id()

pg_current_xact_id()

pg_current_commit_id()

pg_current_xmin_id()

4 / 10

4. Page free space can often become fragmented?

False

True

5 / 10

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

True

False

6 / 10

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

dump

view

clog

heap

7 / 10

7. What does an Item Pointer contain?

choose 3

tuple offset from the start of the page

tuple length

tuple status

tuple xid

8 / 10

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

False

True

9 / 10

9. CLOG Pages are never cached in memory?

True

False

10 / 10

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

COMMIT

MERGE

DELETE

INSERT

Your score is

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