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 is specific for unlogged tables?

free space map

visiblilty map

Initialization fork

Main fork

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

Sysasm Catalog

Sysaux Catalog

System Catalog

Sys Catalog

4 / 20

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

StartNewPG

CreatePGC

Initialize

CreateCluster

5 / 20

5. Tablespaces are used to define physical data layout?

True

False

6 / 20

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

postman

postgres

pginit

init

7 / 20

7. To understand each other, a client and a server must use one and the same interfacing protocol?

False

True

8 / 20

8. TOAST tables reside in a seperate schema?

True

False

9 / 20

9. Which 3 databases exist directly after cluster initialization?

choose 3 options

template1

postgres

template0

sysaux

10 / 20

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

Choose 2 option

Aurora

Postgres Server

Instance

Quorum

11 / 20

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

True

False

12 / 20

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

True

False

13 / 20

13. What is the default standard size for a fork file?

1GB

1MB

5GB

5MB

14 / 20

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

15 / 20

15. Files are logically split into pages?

True

False

16 / 20

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

write-ahead log (WAL)

online redo logs (ORL)

undo segments (UNDO)

rollback segments (RBS)

17 / 20

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

True

False

18 / 20

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

False

True

19 / 20

19. Which fork contains the actual table data?

visiblilty map

free space map

table map

Main fork

20 / 20

20. What is the purpose of autovacuum?

Rebuilds indexes with b level greater than 2

Deletes old logs and traces on disk

Removes stale data from tables and indexes

Performs a backup of WAL logs

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

False

True

2 / 10

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

True

False

3 / 10

3. 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

4 / 10

4. The SQL standard specifies three isolation levels?

True

False

5 / 10

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

True

False

6 / 10

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

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

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

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

reading data direct from memory using pg_dirt

7 / 10

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

True

False

8 / 10

8. non-repeatable read anomaly occurs when?

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 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.

9 / 10

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

False

True

10 / 10

10. What is the default Isolation Level?

Serializable

Repeatable Read

Read Uncommitted

Read Committed

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 free space can often become fragmented?

False

True

2 / 10

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

COMMIT

CREATE

DELETE

INSERT

3 / 10

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

True

False

4 / 10

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

choose 2

flashback block

page header

undo segment

free space

5 / 10

5. When a transaction is committed Postgres uses a special <replace with answer> structure?

commit log

redo log

archive log

transaction log

6 / 10

6. Indexes values also support multi versioning with several versions of an index value existing at any point in time?

False

True

7 / 10

7. Tuples can also be referred to as columns?

False

True

8 / 10

8. What does an Item Pointer contain?

choose 3

tuple xid

tuple offset from the start of the page

tuple length

tuple status

9 / 10

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

pg_current_commit_id()

pg_current_xmin_id()

pg_current_xact_id()

pg_current_id()

10 / 10

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

True

False

Your score is

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