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. What command is used to create the Postgres cluster?

CreateCluster

Initialize

CreatePGC

StartNewPG

2 / 20

2. What is the purpose of the public schema?

no such schema

default schema for user objects

restricted schema for postgres internal usage only

schema used for heterogeneous replication

3 / 20

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

False

True

4 / 20

4. What is the purpose of the template0 database?

No such database

Useful for Postgres support Services to debug issues

Useful for creating development schemas

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

5 / 20

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

True

False

6 / 20

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

7 / 20

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

BREAD

TOAST

BAKE

GROW

8 / 20

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

free space map

vacuum space map

wal space map

used space map

9 / 20

9. What is the name of the 2 default tablespaces created after initialization?

choose 2

pg_default

pg_global

pg_temp

pg_tablespace

10 / 20

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

pginit

init

postman

postgres

11 / 20

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

pg_tabspace

pg_tablespace

pg_tblspc

pg_symlinks

12 / 20

12. What is another name for the postgres process?

postmanager

postmaster

masterprocess

aurora

13 / 20

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

oid

obj

oid#

obj#

14 / 20

14. What is a schema?

A memory area used to cache data from LRU chains

This is the same as a user in Postgres

Namespace that store all objects of a database

The name used to refer to a super user account

15 / 20

15. System Catalog tables begin with which prefix?

sys_

dba_

cat_

pg_

16 / 20

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

Paul Sammy

Egor Rogov

Dan Brown

Sam Altman

17 / 20

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

False

True

18 / 20

18. What is the purpose of the template1 database?

No such database

regular database that you can use at your discretion

database used for temporary tables

a template for all the other databases

19 / 20

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

True

False

20 / 20

20. Which fork contains the actual table data?

free space map

Main fork

table map

visiblilty map

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. 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 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.

2 / 10

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

False

True

3 / 10

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

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

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

4 / 10

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

Select more than 1 answer below:

Apply explicit locks

Issues a rollback after the commit to satisfy repeatable read.

Use a single SQL operator

Replace procedural code with declarative one.

5 / 10

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

ACID

SOC2

HIPPA

SAFE

6 / 10

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

Repeatable Read

Read Uncommitted

Read Committed

Serializable

7 / 10

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

choose 3

Repeatable Read

Read Committed

Read Uncommitted

Serializable

8 / 10

8. 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.

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.

A transactions inserts a null value into a not null columns and commits

9 / 10

9. The more locks a transaction acquires, the better it is isolated from other transactions?

True

False

10 / 10

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

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. If a transaction is read only which kind of Transaction ID is it allocated?

heap XID

virtual XID

magic XID

temporary XID

2 / 10

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

False

True

3 / 10

3. Which 2 of the below represent transaction IDs used for row versioning?

xid

xmax

xtime

xmin

4 / 10

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

pg_current_commit_id()

pg_current_xact_id()

pg_current_xmin_id()

pg_current_id()

5 / 10

5. CLOG files are stored in which directory?

PGDATA/pg_commit

PGDATA/pg_clog

PGDATA/clog

PGDATA/pg_xact

6 / 10

6. Page free space can often become fragmented?

False

True

7 / 10

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

False

True

8 / 10

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

False

True

9 / 10

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

False

True

10 / 10

10. Each page has a layer that usually consists of?

choose 2

flashback block

page header

undo segment

free space

Your score is

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