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 keeps track of available space within pages?

wal space map

vacuum space map

used space map

free space map

2 / 20

2. 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

3 / 20

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

CreatePGC

Initialize

CreateCluster

StartNewPG

4 / 20

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

True

False

5 / 20

5. What is the purpose of wal writer?

collects usage statistics for the instance.

flushes dirty pages to disk.

executes checkpoints

writes WAL entries to disk

6 / 20

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

True

False

7 / 20

7. What is another name for the postgres process?

postmanager

postmaster

aurora

masterprocess

8 / 20

8. How does Postgres know which schema to use if not specified?

Schema Path

Directory Path

Access Path

Search Path

9 / 20

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

Egor Rogov

Dan Brown

Sam Altman

Paul Sammy

10 / 20

10. Users should not modify the template0 database

True

False

11 / 20

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

choose 3

indexes

triggers

tables

sequences

12 / 20

12. What is the purpose of autovacuum?

Removes stale data from tables and indexes

Performs a backup of WAL logs

Deletes old logs and traces on disk

Rebuilds indexes with b level greater than 2

13 / 20

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

False

True

14 / 20

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

System Catalog

Sysasm Catalog

Sysaux Catalog

Sys Catalog

15 / 20

15. TOAST tables reside in a seperate schema?

False

True

16 / 20

16. Which fork is specific for unlogged tables?

visiblilty map

Main fork

Initialization fork

free space map

17 / 20

17. What is the purpose of the visibility map?

shows referential relationships for tables

shows a page to be vacuumed or frozen

provides the data decryption key

provides an audit trail for the database

18 / 20

18. The default Page size is 2k?

True

False

19 / 20

19. What is the purpose of the template0 database?

Useful for creating development schemas

Useful for Postgres support Services to debug issues

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

No such database

20 / 20

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

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. Which of the below are valid Isolations Levels?

choose 2

Random Scatter

Rollback Read

Serializable

Read Committed

3 / 10

3. Which isolation level in theory could mean an application does not have to consider isolation anomalies?

Read Uncommitted

Repeatable Read

Serializable

Read Committed

4 / 10

4. 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

5 / 10

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

False

True

6 / 10

6. Which parameters sets the database default isolation level?

default_isolation_level

default_transaction_isolation

transaction_isolation_level

active_transaction_isolation

7 / 10

7. 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.

8 / 10

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

False

True

9 / 10

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

SAFE

ACID

SOC2

HIPPA

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.

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

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. Which of the below are true about a Pages Item Pointer?

Also know as the pages table of contents

stored in PGDATA/itemptr directory

Each pointer uses 4 bytes

Each pointer uses 8 bytes

2 / 10

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

transaction log

commit log

archive log

redo log

3 / 10

3. Tuples can also be referred to as columns?

True

False

4 / 10

4. Page free space can often become fragmented?

False

True

5 / 10

5. indexes do not use row versioning?

False

True

6 / 10

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

True

False

7 / 10

7. The page header stores checksum and the sizes of the other parts of the page?

False

True

8 / 10

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

True

False

9 / 10

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

True

False

10 / 10

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

True

False

Your score is

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