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 default standard size for a fork file?

5GB

5MB

1MB

1GB

2 / 20

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

False

True

3 / 20

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

False

True

4 / 20

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

pginit

postgres

init

postman

5 / 20

5. Which of below are predefined schemas?

choose 3

information_schema

pg_temp

pg_toast

pg_schema

6 / 20

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

Choose 2 option

Postgres Server

Instance

Aurora

Quorum

7 / 20

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

False

True

8 / 20

8. Which 3 databases exist directly after cluster initialization?

choose 3 options

template0

postgres

sysaux

template1

9 / 20

9. What is the purpose of the template0 database?

No such database

Useful for creating development schemas

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

Useful for Postgres support Services to debug issues

10 / 20

10. Each Database has its own System Catalog?

False

True

11 / 20

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

True

False

12 / 20

12. What is the purpose of autovacuum?

Rebuilds indexes with b level greater than 2

Deletes old logs and traces on disk

Performs a backup of WAL logs

Removes stale data from tables and indexes

13 / 20

13. Which of below are predefined schemas?

choose 2

public

system

pg_catalog

postgres

14 / 20

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

True

False

15 / 20

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

False

True

16 / 20

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

choose 2

pg_default

pg_tablespace

pg_global

pg_temp

17 / 20

17. Users should not modify the template0 database

True

False

18 / 20

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

19 / 20

19. 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 temporary tables that are common to the whole cluster

stores user tables that are common to the whole cluster

20 / 20

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

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. 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.

2 / 10

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

True

False

3 / 10

3. Which parameters sets the database default isolation level?

active_transaction_isolation

transaction_isolation_level

default_transaction_isolation

default_isolation_level

4 / 10

4. 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 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 transactions issues a commit, then a rollback to restore data to its original value

5 / 10

5. What is the acronym used for the attributes that ensure Data consistency, integrity and durability?

ACID

HIPPA

SAFE

SOC2

6 / 10

6. Which of the below are valid Isolations Levels?

choose 2

Serializable

Read Committed

Random Scatter

Rollback Read

7 / 10

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

False

True

8 / 10

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

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

reading data direct from memory using pg_dirt

9 / 10

9. The SQL standard specifies three isolation levels?

False

True

10 / 10

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

False

True

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

False

True

2 / 10

2. The page Special Space is located at the start of the page with highest address

True

False

3 / 10

3. status of a subtransaction is written into CLOG?

False

True

4 / 10

4. Page free space can often become fragmented?

True

False

5 / 10

5. CLOG contains how many bits for each transaction?

6 / 10

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

True

False

7 / 10

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

magic XID

heap XID

virtual XID

temporary XID

8 / 10

8. Information about subtransactions is stored under?

PGDATA/pg_min

PGDATA/pg_subtrans

PGDATA/pg_xid

PGDATA/subtrans

9 / 10

9. virtual IDs exist only in PGDATA/pg_vxid when not cached?

True

False

10 / 10

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

xtime

xid

xmin

xmax

Your score is

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