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. Which fork contains the actual table data?

Main fork

visiblilty map

free space map

table map

2 / 20

2. What column in system catalogs servers as the Primary Key

obj#

oid

oid#

obj

3 / 20

3. What is the purpose of wal writer?

collects usage statistics for the instance.

executes checkpoints

flushes dirty pages to disk.

writes WAL entries to disk

4 / 20

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

True

False

5 / 20

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

choose 2

pg_temp

pg_tablespace

pg_default

pg_global

6 / 20

6. What is the purpose of the visibility map?

shows referential relationships for tables

provides the data decryption key

shows a page to be vacuumed or frozen

provides an audit trail for the database

7 / 20

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

choose 3

triggers

tables

sequences

indexes

8 / 20

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

9 / 20

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

False

True

10 / 20

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

wal space map

used space map

free space map

vacuum space map

11 / 20

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

False

True

12 / 20

12. What is the purpose of the template1 database?

No such database

database used for temporary tables

a template for all the other databases

regular database that you can use at your discretion

13 / 20

13. Which of below are predefined schemas?

choose 2

pg_catalog

public

postgres

system

14 / 20

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

False

True

15 / 20

15. TOAST tables reside in a seperate schema?

False

True

16 / 20

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

Dan Brown

Paul Sammy

Egor Rogov

Sam Altman

17 / 20

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

free space map

table map

visiblilty map

Main fork

18 / 20

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

True

False

19 / 20

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

False

True

20 / 20

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

pg_tables

pg_class

pg_system

pg_catalog

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. 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 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.

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

2 / 10

2. Which parameters sets the database default isolation level?

transaction_isolation_level

active_transaction_isolation

default_isolation_level

default_transaction_isolation

3 / 10

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

True

False

4 / 10

4. 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 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.

A transaction reads one and the same row once and modifies this row and commits the change.

5 / 10

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

False

True

6 / 10

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

True

False

7 / 10

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

choose 3

Serializable

Repeatable Read

Read Committed

Read Uncommitted

8 / 10

8. Which of the below are valid Isolations Levels?

choose 2

Serializable

Rollback Read

Read Committed

Random Scatter

9 / 10

9. The SQL standard specifies three isolation levels?

True

False

10 / 10

10. What is the default Isolation Level?

Read Uncommitted

Read Committed

Serializable

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

True

False

2 / 10

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

pg_current_xmin_id()

pg_current_id()

pg_current_commit_id()

pg_current_xact_id()

3 / 10

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

False

True

4 / 10

4. To identify different versions of one and the same row, PostgreSQL marks each of them with which two value?

xmin

xmas

xid

xmax

5 / 10

5. Page free space can often become fragmented?

False

True

6 / 10

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

False

True

7 / 10

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

view

heap

dump

clog

8 / 10

8. Information about subtransactions is stored under?

PGDATA/pg_subtrans

PGDATA/subtrans

PGDATA/pg_xid

PGDATA/pg_min

9 / 10

9. Postgres table physical data files are always cross compatible across platforms?

False

True

10 / 10

10. Tuples can also be referred to as columns?

False

True

Your score is

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