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. 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

2 / 20

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

Paul Sammy

Egor Rogov

Sam Altman

Dan Brown

3 / 20

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

table map

Main fork

free space map

visiblilty map

4 / 20

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

False

True

5 / 20

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

False

True

6 / 20

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

TOAST

BAKE

GROW

BREAD

7 / 20

7. Each Database has its own System Catalog?

True

False

8 / 20

8. Which 3 databases exist directly after cluster initialization?

choose 3 options

template0

sysaux

template1

postgres

9 / 20

9. If we create a new tablespace which directory will symbolic links be created from?

pg_tblspc

pg_symlinks

pg_tablespace

pg_tabspace

10 / 20

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

online redo logs (ORL)

rollback segments (RBS)

write-ahead log (WAL)

undo segments (UNDO)

11 / 20

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

vacuum space map

wal space map

used space map

free space map

12 / 20

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

False

True

13 / 20

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

True

False

14 / 20

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

15 / 20

15. What is the purpose of the template1 database?

No such database

a template for all the other databases

regular database that you can use at your discretion

database used for temporary tables

16 / 20

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

Sys Catalog

Sysasm Catalog

Sysaux Catalog

System Catalog

17 / 20

17. The default Page size is 2k?

False

True

18 / 20

18. Users should not modify the template0 database

False

True

19 / 20

19. TOAST tables reside in a seperate schema?

True

False

20 / 20

20. System Catalog tables begin with which prefix?

dba_

cat_

sys_

pg_

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 parameters sets the database default isolation level?

active_transaction_isolation

default_transaction_isolation

default_isolation_level

transaction_isolation_level

2 / 10

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

True

False

3 / 10

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

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

4 / 10

4. Which of the below are valid Isolations Levels?

choose 2

Rollback Read

Random Scatter

Read Committed

Serializable

5 / 10

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

True

False

6 / 10

6. The SQL standard specifies three isolation levels?

True

False

7 / 10

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

True

False

8 / 10

8. 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 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.

9 / 10

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

False

True

10 / 10

10. 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 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

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.

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

False

True

2 / 10

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

choose 2

free space

flashback block

undo segment

page header

3 / 10

3. indexes do not use row versioning?

False

True

4 / 10

4. Information about subtransactions is stored under?

PGDATA/subtrans

PGDATA/pg_xid

PGDATA/pg_min

PGDATA/pg_subtrans

5 / 10

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

clog

heap

view

dump

6 / 10

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

INSERT

CREATE

COMMIT

DELETE

7 / 10

7. What does an Item Pointer contain?

choose 3

tuple offset from the start of the page

tuple length

tuple status

tuple xid

8 / 10

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

DELETE

INSERT

MERGE

COMMIT

9 / 10

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

magic XID

heap XID

virtual XID

temporary XID

10 / 10

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

False

True

Your score is

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