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. Users should not modify the template0 database

True

False

2 / 20

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

choose 3

sequences

indexes

triggers

tables

3 / 20

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

Choose 2 option

Aurora

Postgres Server

Instance

Quorum

4 / 20

4. TOAST tables reside in a seperate schema?

True

False

5 / 20

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

write-ahead log (WAL)

undo segments (UNDO)

online redo logs (ORL)

rollback segments (RBS)

6 / 20

6. Postgres uses a thread based process model?

False

True

7 / 20

7. Which of below are predefined schemas?

choose 3

information_schema

pg_toast

pg_schema

pg_temp

8 / 20

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

False

True

9 / 20

9. The pg_default tablespace should never be used to create user tables?

True

False

10 / 20

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

True

False

11 / 20

11. What is the purpose of the public schema?

schema used for heterogeneous replication

default schema for user objects

restricted schema for postgres internal usage only

no such schema

12 / 20

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

True

False

13 / 20

13. What is the point of the pg_global tablespace?

stores WAL logs used for global replication

stores system catalog objects that are common to the whole cluster

stores user tables that are common to the whole cluster

stores temporary tables that are common to the whole cluster

14 / 20

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

True

False

15 / 20

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

16 / 20

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

pg_symlinks

pg_tblspc

pg_tablespace

pg_tabspace

17 / 20

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

False

True

18 / 20

18. Which 3 databases exist directly after cluster initialization?

choose 3 options

postgres

template0

template1

sysaux

19 / 20

19. What is the purpose of the postgres database?

a template for all the other database

regular database that you can use at your discretion

No such database

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

20 / 20

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

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. What is the default Isolation Level?

Read Committed

Read Uncommitted

Serializable

Repeatable Read

2 / 10

2. 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 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 and commits the change.

3 / 10

3. A phantom read anomaly occurs when?

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

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.

4 / 10

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

True

False

5 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

6 / 10

6. Which parameters sets the database default isolation level?

active_transaction_isolation

default_isolation_level

transaction_isolation_level

default_transaction_isolation

7 / 10

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

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

8 / 10

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

False

True

9 / 10

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

choose 3

Serializable

Repeatable Read

Read Uncommitted

Read Committed

10 / 10

10. Which of the below are valid Isolations Levels?

choose 2

Serializable

Rollback Read

Read Committed

Random Scatter

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

True

False

2 / 10

2. psql provides a special mode that allows you to continue a transaction after a failure?

True

False

3 / 10

3. status of a subtransaction is written into CLOG?

True

False

4 / 10

4. Which 2 items does a Virtual XID consist of?

sequential number

xmin

checksum

backend process ID

5 / 10

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

xmin

xtime

xmax

xid

6 / 10

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

archive log

transaction log

redo log

commit log

7 / 10

7. index row headers like table row headers contain xmin and xmax fields?

False

True

8 / 10

8. Rows of TOAST tables are handled in such a way that they are never update?

True

False

9 / 10

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

xmin

xmas

xid

xmax

10 / 10

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

True

False

Your score is

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