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

2 / 20

2. What is the purpose of the postgres database?

No such database

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

regular database that you can use at your discretion

a template for all the other database

3 / 20

3. What is another name for the postgres process?

postmanager

masterprocess

postmaster

aurora

4 / 20

4. The default Page size is 2k?

False

True

5 / 20

5. 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

6 / 20

6. 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

7 / 20

7. TOAST tables reside in a seperate schema?

True

False

8 / 20

8. What 3 files/forks as a minimum make up a table on disk?

free space map

Main fork

visiblilty map

table map

9 / 20

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

True

False

10 / 20

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

Choose 2 option

Aurora

Postgres Server

Quorum

Instance

11 / 20

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

False

True

12 / 20

12. What is the purpose of the public schema?

schema used for heterogeneous replication

restricted schema for postgres internal usage only

no such schema

default schema for user objects

13 / 20

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

True

False

14 / 20

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

True

False

15 / 20

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

GROW

BAKE

BREAD

TOAST

16 / 20

16. Which fork contains the actual table data?

Main fork

free space map

table map

visiblilty map

17 / 20

17. If we create a new tablespace which directory will symbolic links be created from?

pg_tablespace

pg_tabspace

pg_symlinks

pg_tblspc

18 / 20

18. What is the point of the pg_global tablespace?

stores temporary tables that are common to the whole cluster

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

19 / 20

19. Which fork is specific for unlogged tables?

Main fork

visiblilty map

free space map

Initialization fork

20 / 20

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

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. Which of the below are valid Isolations Levels?

choose 2

Rollback Read

Random Scatter

Read Committed

Serializable

2 / 10

2. 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

3 / 10

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

True

False

4 / 10

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

Repeatable Read

Serializable

Read Committed

Read Uncommitted

5 / 10

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

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

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

6 / 10

6. The SQL standard specifies three isolation levels?

False

True

7 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

8 / 10

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

Select more than 1 answer below:

Replace procedural code with declarative one.

Issues a rollback after the commit to satisfy repeatable read.

Use a single SQL operator

Apply explicit locks

9 / 10

9. Which parameters sets the database default isolation level?

active_transaction_isolation

default_isolation_level

default_transaction_isolation

transaction_isolation_level

10 / 10

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

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

False

True

2 / 10

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

heap

view

clog

dump

3 / 10

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

False

True

4 / 10

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

True

False

5 / 10

5. status of a subtransaction is written into CLOG?

False

True

6 / 10

6. Information about subtransactions is stored under?

PGDATA/pg_xid

PGDATA/pg_min

PGDATA/pg_subtrans

PGDATA/subtrans

7 / 10

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

True

False

8 / 10

8. Page header sizes can be easily displayed using the <choose from answers> extension

pagesize

pagedetect

pageinspect

pageheadinfo

9 / 10

9. CLOG contains how many bits for each transaction?

10 / 10

10. a transaction containing a savepoint is will still be considered as only a single transaction?

True

False

Your score is

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