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 server spawns a new backend session for each connection?

False

True

2 / 20

2. What is a schema?

This is the same as a user in Postgres

A memory area used to cache data from LRU chains

The name used to refer to a super user account

Namespace that store all objects of a database

3 / 20

3. What is the purpose of the template0 database?

No such database

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

Useful for Postgres support Services to debug issues

Useful for creating development schemas

4 / 20

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

Choose 2 option

Quorum

Aurora

Postgres Server

Instance

5 / 20

5. What is the point of the pg_global tablespace?

stores system catalog objects that are common to the whole cluster

stores user tables that are common to the whole cluster

stores WAL logs used for global replication

stores temporary tables that are common to the whole cluster

6 / 20

6. Which of below are predefined schemas?

choose 2

system

public

postgres

pg_catalog

7 / 20

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

True

False

8 / 20

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

True

False

9 / 20

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

5MB

5GB

1GB

1MB

10 / 20

10. What is another name for the postgres process?

postmanager

postmaster

aurora

masterprocess

11 / 20

11. What is the name of the mechanism used to store a row bigger than a page size?

TOAST

BREAD

BAKE

GROW

12 / 20

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

pg_catalog

pg_class

pg_tables

pg_system

13 / 20

13. What is the purpose of autovacuum?

Deletes old logs and traces on disk

Performs a backup of WAL logs

Rebuilds indexes with b level greater than 2

Removes stale data from tables and indexes

14 / 20

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

True

False

15 / 20

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

postman

init

postgres

pginit

16 / 20

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

True

False

17 / 20

17. Postgres uses a thread based process model?

False

True

18 / 20

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

False

True

19 / 20

19. Which of below are predefined schemas?

choose 3

pg_schema

pg_temp

information_schema

pg_toast

20 / 20

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

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

choose 3

Serializable

Read Uncommitted

Repeatable Read

Read Committed

2 / 10

2. Which of the below are valid Isolations Levels?

choose 2

Read Committed

Serializable

Random Scatter

Rollback Read

3 / 10

3. Which parameters sets the database default isolation level?

default_isolation_level

transaction_isolation_level

default_transaction_isolation

active_transaction_isolation

4 / 10

4. 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

Issues a rollback after the commit to satisfy repeatable read.

Replace procedural code with declarative one.

Apply explicit locks

5 / 10

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

False

True

6 / 10

6. 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 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 issue a rollback.

A transaction reads one and the same row twice, another transaction modifies this row between these reads and commits the change.

7 / 10

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

Read Committed

Read Uncommitted

Repeatable Read

Serializable

8 / 10

8. What is the default Isolation Level?

Read Uncommitted

Read Committed

Repeatable Read

Serializable

9 / 10

9. The SQL standard specifies three isolation levels?

False

True

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 transaction executes two identical queries returning a set of rows that satisfy a particular condition, while another transaction also queries this same data.

The same transactions issues a commit, then a rollback to restore data to its original value

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

redo log

commit log

archive log

2 / 10

2. Page free space can often become fragmented?

True

False

3 / 10

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

True

False

4 / 10

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

stored in PGDATA/itemptr directory

Also know as the pages table of contents

Each pointer uses 8 bytes

Each pointer uses 4 bytes

5 / 10

5. Tuples can also be referred to as columns?

False

True

6 / 10

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

xmax

xmin

xmas

xid

7 / 10

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

False

True

8 / 10

8. indexes do not use row versioning?

False

True

9 / 10

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

False

True

10 / 10

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

True

False

Your score is

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