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

Choose 2 option

Postgres Server

Aurora

Instance

Quorum

2 / 20

2. Which of the below objects can be referred to as relations?

choose 3

tables

triggers

sequences

indexes

3 / 20

3. What is the purpose of autovacuum?

Performs a backup of WAL logs

Deletes old logs and traces on disk

Rebuilds indexes with b level greater than 2

Removes stale data from tables and indexes

4 / 20

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

Schema Path

Directory Path

Search Path

Access Path

5 / 20

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

True

False

6 / 20

6. Which 3 databases exist directly after cluster initialization?

choose 3 options

sysaux

postgres

template1

template0

7 / 20

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

Initialize

CreatePGC

CreateCluster

StartNewPG

8 / 20

8. Files are logically split into pages?

False

True

9 / 20

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

undo segments (UNDO)

write-ahead log (WAL)

online redo logs (ORL)

rollback segments (RBS)

10 / 20

10. Which of below are predefined schemas?

choose 3

information_schema

pg_schema

pg_toast

pg_temp

11 / 20

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

free space map

Main fork

visiblilty map

table map

12 / 20

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

True

False

13 / 20

13. What is the purpose of the postgres database?

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

regular database that you can use at your discretion

No such database

a template for all the other database

14 / 20

14. System Catalog tables begin with which prefix?

dba_

cat_

sys_

pg_

15 / 20

15. The default Page size is 2k?

False

True

16 / 20

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

True

False

17 / 20

17. What is a schema?

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

Namespace that store all objects of a database

18 / 20

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

init

pginit

postman

postgres

19 / 20

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

Sam Altman

Paul Sammy

Egor Rogov

Dan Brown

20 / 20

20. What is the point of the pg_global tablespace?

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

stores WAL logs used for global replication

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

False

True

3 / 10

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

Select more than 1 answer below:

Apply explicit locks

Replace procedural code with declarative one.

Issues a rollback after the commit to satisfy repeatable read.

Use a single SQL operator

4 / 10

4. A phantom read anomaly occurs when?

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

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.

5 / 10

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

True

False

6 / 10

6. What is the default Isolation Level?

Read Uncommitted

Serializable

Read Committed

Repeatable Read

7 / 10

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

choose 3

Serializable

Repeatable Read

Read Uncommitted

Read Committed

8 / 10

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

Serializable

Read Committed

Read Uncommitted

Repeatable Read

9 / 10

9. non-repeatable read anomaly occurs when?

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 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 twice, another transaction modifies this row between these reads and commits the change.

10 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

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

pageheadinfo

pagesize

pageinspect

pagedetect

2 / 10

2. Page free space can often become fragmented?

False

True

3 / 10

3. status of a subtransaction is written into CLOG?

False

True

4 / 10

4. index row headers like table row headers contain xmin and xmax fields?

True

False

5 / 10

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

pg_current_id()

pg_current_commit_id()

pg_current_xact_id()

pg_current_xmin_id()

6 / 10

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

True

False

7 / 10

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

True

False

8 / 10

8. Tuples can also be referred to as columns?

True

False

9 / 10

9. What does an Item Pointer contain?

choose 3

tuple offset from the start of the page

tuple status

tuple xid

tuple length

10 / 10

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

xtime

xid

xmax

xmin

Your score is

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