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 default Page size is 2k?

False

True

2 / 20

2. Which fork is specific for unlogged tables?

visiblilty map

free space map

Main fork

Initialization fork

3 / 20

3. What is the name of the 2 default tablespaces created after initialization?

choose 2

pg_tablespace

pg_temp

pg_default

pg_global

4 / 20

4. Users should not modify the template0 database

False

True

5 / 20

5. A Postgres cluster consists of 2 or more physical servers accessing one Postgres Instance?

True

False

6 / 20

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

pg_tables

pg_system

pg_class

pg_catalog

7 / 20

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

8 / 20

8. What is a schema?

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

Namespace that store all objects of a database

9 / 20

9. What is the name of the catalog that stores metadata for all cluster objects?

Sys Catalog

System Catalog

Sysasm Catalog

Sysaux Catalog

10 / 20

10. TOAST tables reside in a seperate schema?

False

True

11 / 20

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

PGCORE

PGDATA

PGTIPS

PGBASE

12 / 20

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

False

True

13 / 20

13. What is another name for the postgres process?

aurora

postmanager

postmaster

masterprocess

14 / 20

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

False

True

15 / 20

15. Each Database has its own System Catalog?

False

True

16 / 20

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

Directory Path

Schema Path

Access Path

Search Path

17 / 20

17. What is the purpose of the postgres database?

a template for all the other database

No such database

regular database that you can use at your discretion

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

18 / 20

18. Some System Catalog tables are common to all databases in the cluster?

True

False

19 / 20

19. What is the purpose of autovacuum?

Performs a backup of WAL logs

Deletes old logs and traces on disk

Removes stale data from tables and indexes

Rebuilds indexes with b level greater than 2

20 / 20

20. Which of below are predefined schemas?

choose 3

pg_toast

information_schema

pg_schema

pg_temp

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. Which of the below would best describe a dirty read?

a session being able to see commited data altered by another session

reading data direct from memory using pg_dirt

reading the data directly from file using a text editor such as vi or notepad

a session being able to see uncommited data altered by another session

2 / 10

2. 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;

3 / 10

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

choose 3

Read Committed

Read Uncommitted

Repeatable Read

Serializable

4 / 10

4. 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.

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

5 / 10

5. 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 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.

6 / 10

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

True

False

7 / 10

7. 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.

Apply explicit locks

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

8 / 10

8. What is the default Isolation Level?

Repeatable Read

Read Uncommitted

Read Committed

Serializable

9 / 10

9. Which of the below are valid Isolations Levels?

choose 2

Random Scatter

Serializable

Rollback Read

Read Committed

10 / 10

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

False

True

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

xtime

xmax

xmin

xid

2 / 10

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

choose 2

page header

undo segment

free space

flashback block

3 / 10

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

False

True

4 / 10

4. The page header stores checksum and the sizes of the other parts of the page?

True

False

5 / 10

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

heap XID

virtual XID

magic XID

temporary XID

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. a transaction containing a savepoint is will still be considered as only a single transaction?

False

True

8 / 10

8. Tuples can also be referred to as columns?

False

True

9 / 10

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

DELETE

INSERT

MERGE

COMMIT

10 / 10

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

pg_current_commit_id()

pg_current_id()

pg_current_xact_id()

pg_current_xmin_id()

Your score is

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