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

True

False

2 / 20

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

Sam Altman

Paul Sammy

Egor Rogov

Dan Brown

3 / 20

3. Which fork keeps track of available space within pages?

wal space map

used space map

free space map

vacuum space map

4 / 20

4. TOAST tables reside in a seperate schema?

True

False

5 / 20

5. What is the point of the pg_global tablespace?

stores user tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

stores temporary tables that are common to the whole cluster

stores WAL logs used for global replication

6 / 20

6. What is the purpose of the template0 database?

Useful for Postgres support Services to debug issues

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

No such database

Useful for creating development schemas

7 / 20

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

8 / 20

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

9 / 20

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

choose 2

pg_tablespace

pg_temp

pg_global

pg_default

10 / 20

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

True

False

11 / 20

11. Which of below are predefined schemas?

choose 3

pg_temp

pg_schema

pg_toast

information_schema

12 / 20

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

Directory Path

Access Path

Schema Path

Search Path

13 / 20

13. Files are logically split into pages?

True

False

14 / 20

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

choose 3

tables

sequences

indexes

triggers

15 / 20

15. System Catalog tables begin with which prefix?

sys_

dba_

cat_

pg_

16 / 20

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

True

False

17 / 20

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

True

False

18 / 20

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

True

False

19 / 20

19. What is the purpose of the postgres database?

regular database that you can use at your discretion

No such database

a template for all the other database

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

20 / 20

20. Users should not modify the template0 database

True

False

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

choose 3

Serializable

Read Uncommitted

Read Committed

Repeatable Read

2 / 10

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

False

True

3 / 10

3. Which of the below are valid Isolations Levels?

choose 2

Random Scatter

Serializable

Rollback Read

Read Committed

4 / 10

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

False

True

5 / 10

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

False

True

6 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

7 / 10

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

False

True

8 / 10

8. Which parameters sets the database default isolation level?

default_isolation_level

active_transaction_isolation

transaction_isolation_level

default_transaction_isolation

9 / 10

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

10 / 10

10. A phantom read anomaly occurs when?

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

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.

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

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. The page header is located in the highest address?

True

False

2 / 10

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

virtual XID

temporary XID

heap XID

magic XID

3 / 10

3. What does an Item Pointer contain?

choose 3

tuple xid

tuple offset from the start of the page

tuple length

tuple status

4 / 10

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

False

True

5 / 10

5. at any one time Postgres can have several versions of a row?

False

True

6 / 10

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

CREATE

INSERT

DELETE

COMMIT

7 / 10

7. Which of the below are true about a Pages Item Pointer?

stored in PGDATA/itemptr directory

Each pointer uses 4 bytes

Each pointer uses 8 bytes

Also know as the pages table of contents

8 / 10

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

pagedetect

pagesize

pageheadinfo

pageinspect

9 / 10

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

choose 2

page header

undo segment

free space

flashback block

10 / 10

10. If a transaction aborts, all page changes are reverted(rolled back) in place?

True

False

Your score is

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