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. Postgres by default has built in connection pooling abilities?

True

False

2 / 20

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

False

True

3 / 20

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

vacuum space map

free space map

wal space map

used space map

4 / 20

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

rollback segments (RBS)

write-ahead log (WAL)

undo segments (UNDO)

online redo logs (ORL)

5 / 20

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

True

False

6 / 20

6. What is the purpose of the visibility map?

provides the data decryption key

provides an audit trail for the database

shows a page to be vacuumed or frozen

shows referential relationships for tables

7 / 20

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

Paul Sammy

Dan Brown

Egor Rogov

Sam Altman

8 / 20

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

Sysaux Catalog

System Catalog

Sysasm Catalog

Sys Catalog

9 / 20

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

oid

oid#

obj#

obj

10 / 20

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

5GB

1MB

1GB

5MB

11 / 20

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

12 / 20

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

pg_class

pg_catalog

pg_tables

pg_system

13 / 20

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

False

True

14 / 20

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

False

True

15 / 20

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

True

False

16 / 20

16. Which of below are predefined schemas?

choose 2

pg_catalog

public

postgres

system

17 / 20

17. What is the point of the pg_global tablespace?

stores user tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

stores WAL logs used for global replication

stores temporary tables that are common to the whole cluster

18 / 20

18. What is a schema?

This is the same as a user in Postgres

A memory area used to cache data from LRU chains

Namespace that store all objects of a database

The name used to refer to a super user account

19 / 20

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

pginit

postgres

postman

init

20 / 20

20. The default Page size is 2k?

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

True

False

2 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

3 / 10

3. The SQL standard specifies three isolation levels?

False

True

4 / 10

4. Which of the below are valid Isolations Levels?

choose 2

Serializable

Rollback Read

Random Scatter

Read Committed

5 / 10

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

True

False

6 / 10

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

False

True

7 / 10

7. What are some of database features we can use to avoid a non repeatable read?

Select more than 1 answer below:

Use a single SQL operator

Apply explicit locks

Issues a rollback after the commit to satisfy repeatable read.

Replace procedural code with declarative one.

8 / 10

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

choose 3

Read Uncommitted

Read Committed

Serializable

Repeatable Read

9 / 10

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

True

False

10 / 10

10. 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 twice, 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.

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

transaction log

archive log

commit log

redo log

2 / 10

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

False

True

3 / 10

3. Page free space can often become fragmented?

False

True

4 / 10

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

False

True

5 / 10

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

xmax

xid

xmas

xmin

6 / 10

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

False

True

7 / 10

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

backend process ID

checksum

xmin

sequential number

8 / 10

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

True

False

9 / 10

9. status of a subtransaction is written into CLOG?

True

False

10 / 10

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

pg_current_id()

pg_current_xmin_id()

pg_current_xact_id()

pg_current_commit_id()

Your score is

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