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?

False

True

2 / 20

2. Tablespaces are used to define physical data layout?

False

True

3 / 20

3. Which 3 databases exist directly after cluster initialization?

choose 3 options

sysaux

template0

template1

postgres

4 / 20

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

True

False

5 / 20

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

GROW

BAKE

TOAST

BREAD

6 / 20

6. How many rows in a page does Postgres aim to have before considering TOAST?

7 / 20

7. System Catalog tables begin with which prefix?

pg_

dba_

cat_

sys_

8 / 20

8. What is the purpose of the template1 database?

No such database

regular database that you can use at your discretion

a template for all the other databases

database used for temporary tables

9 / 20

9. Which fork contains the actual table data?

table map

free space map

Main fork

visiblilty map

10 / 20

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

True

False

11 / 20

11. What is a schema?

The name used to refer to a super user account

This is the same as a user in Postgres

Namespace that store all objects of a database

A memory area used to cache data from LRU chains

12 / 20

12. What is the purpose of autovacuum?

Rebuilds indexes with b level greater than 2

Performs a backup of WAL logs

Deletes old logs and traces on disk

Removes stale data from tables and indexes

13 / 20

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

False

True

14 / 20

14. Each Database has its own System Catalog?

False

True

15 / 20

15. Which of below are predefined schemas?

choose 2

system

public

pg_catalog

postgres

16 / 20

16. What is another name for the postgres process?

postmanager

masterprocess

aurora

postmaster

17 / 20

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

False

True

18 / 20

18. Who is the Author of the Postgres 14 Internals book?

Paul Sammy

Egor Rogov

Dan Brown

Sam Altman

19 / 20

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

postgres

postman

init

pginit

20 / 20

20. What is the purpose of the template0 database?

Useful for Postgres support Services to debug issues

No such database

Useful for creating development schemas

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

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

Select more than 1 answer below:

Apply explicit locks

Use a single SQL operator

Replace procedural code with declarative one.

Issues a rollback after the commit to satisfy repeatable read.

2 / 10

2. What is the default Isolation Level?

Serializable

Repeatable Read

Read Committed

Read Uncommitted

3 / 10

3. non-repeatable read anomaly occurs when?

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.

A transaction reads one and the same row once, another transaction modifies this row between these reads and commits the change.

4 / 10

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

HIPPA

SOC2

SAFE

ACID

5 / 10

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

True

False

6 / 10

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

True

False

7 / 10

7. 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 also queries this same data.

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

A transactions inserts a null value into a not null columns and commits

8 / 10

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

False

True

9 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

10 / 10

10. Which of the below are valid Isolations Levels?

choose 2

Serializable

Read Committed

Rollback Read

Random Scatter

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. status of a subtransaction is written into CLOG?

False

True

2 / 10

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

COMMIT

DELETE

MERGE

INSERT

3 / 10

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

sequential number

checksum

xmin

backend process ID

4 / 10

4. Tuples can also be referred to as columns?

False

True

5 / 10

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

True

False

6 / 10

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

True

False

7 / 10

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

True

False

8 / 10

8. Page free space can often become fragmented?

False

True

9 / 10

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

False

True

10 / 10

10. A page along with its tuples is read into the buffer cache with compression transformations to enhance cache efficiency?

False

True

Your score is

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