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

True

False

2 / 20

2. What is the purpose of the template0 database?

Useful for creating development schemas

Useful for Postgres support Services to debug issues

No such database

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

3 / 20

3. Users should not modify the template0 database

False

True

4 / 20

4. Postgres uses a thread based process model?

True

False

5 / 20

5. What is the purpose of wal writer?

executes checkpoints

writes WAL entries to disk

flushes dirty pages to disk.

collects usage statistics for the instance.

6 / 20

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

7 / 20

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

8 / 20

8. What is the point of the pg_global tablespace?

stores system catalog objects that are common to the whole cluster

stores temporary tables that are common to the whole cluster

stores WAL logs used for global replication

stores user tables that are common to the whole cluster

9 / 20

9. What is the purpose of the public schema?

restricted schema for postgres internal usage only

no such schema

schema used for heterogeneous replication

default schema for user objects

10 / 20

10. The default Page size is 2k?

False

True

11 / 20

11. What is a schema?

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

This is the same as a user in Postgres

12 / 20

12. Postgres server spawns a new backend session for each connection?

False

True

13 / 20

13. What is another name for the postgres process?

masterprocess

postmanager

aurora

postmaster

14 / 20

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

free space map

used space map

wal space map

vacuum space map

15 / 20

15. What is the name of the directory that contains the files related to the Postgres cluster?

PGCORE

PGBASE

PGDATA

PGTIPS

16 / 20

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

Access Path

Directory Path

Search Path

Schema Path

17 / 20

17. Files are logically split into pages?

True

False

18 / 20

18. What is the purpose of autovacuum?

Deletes old logs and traces on disk

Removes stale data from tables and indexes

Rebuilds indexes with b level greater than 2

Performs a backup of WAL logs

19 / 20

19. Which of below are predefined schemas?

choose 3

information_schema

pg_toast

pg_temp

pg_schema

20 / 20

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

CreateCluster

CreatePGC

StartNewPG

Initialize

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?

Serializable

Read Committed

Read Uncommitted

Repeatable Read

2 / 10

2. Which parameters sets the database default isolation level?

default_transaction_isolation

default_isolation_level

transaction_isolation_level

active_transaction_isolation

3 / 10

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

True

False

4 / 10

4. 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 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.

5 / 10

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

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

reading the data directly from file using a text editor such as vi or notepad

reading data direct from memory using pg_dirt

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

6 / 10

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

False

True

7 / 10

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

SAFE

HIPPA

SOC2

ACID

8 / 10

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

choose 3

Repeatable Read

Read Uncommitted

Serializable

Read Committed

9 / 10

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

Serializable

Read Committed

Repeatable Read

Read Uncommitted

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. Each page has a layer that usually consists of?

choose 2

flashback block

page header

free space

undo segment

2 / 10

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

xid

xmax

xmas

xmin

3 / 10

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

Each pointer uses 4 bytes

stored in PGDATA/itemptr directory

Also know as the pages table of contents

Each pointer uses 8 bytes

4 / 10

4. In Postgres, tables are often referred to as which of the below?

heap

view

clog

dump

5 / 10

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

True

False

6 / 10

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

True

False

7 / 10

7. status of a subtransaction is written into CLOG?

False

True

8 / 10

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

True

False

9 / 10

9. When a row is created, its xmin value is set to the transaction ID of which command?

CREATE

DELETE

INSERT

COMMIT

10 / 10

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

False

True

Your score is

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