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 is the default standard size for a fork file?

5MB

5GB

1GB

1MB

2 / 20

2. Which of below are predefined schemas?

choose 2

postgres

pg_catalog

system

public

3 / 20

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

choose 2

pg_temp

pg_global

pg_tablespace

pg_default

4 / 20

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

pg_tables

pg_system

pg_catalog

pg_class

5 / 20

5. Tablespaces are used to define physical data layout?

True

False

6 / 20

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

pg_symlinks

pg_tabspace

pg_tblspc

pg_tablespace

7 / 20

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

True

False

8 / 20

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

9 / 20

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

oid

oid#

obj

obj#

10 / 20

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

False

True

11 / 20

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

False

True

12 / 20

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

Search Path

Access Path

Directory Path

Schema Path

13 / 20

13. Each Database has its own System Catalog?

True

False

14 / 20

14. Which 3 databases exist directly after cluster initialization?

choose 3 options

template0

postgres

template1

sysaux

15 / 20

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

Choose 2 option

Instance

Aurora

Quorum

Postgres Server

16 / 20

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

False

True

17 / 20

17. What is the purpose of wal writer?

executes checkpoints

collects usage statistics for the instance.

flushes dirty pages to disk.

writes WAL entries to disk

18 / 20

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

False

True

19 / 20

19. A single Postgres Instance can server only one database?

False

True

20 / 20

20. Users should not modify the template0 database

False

True

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 statements will start a transaction as Read Repeatable?

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

2 / 10

2. 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.

Apply explicit locks

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

3 / 10

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

False

True

4 / 10

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

reading data direct from memory using pg_dirt

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

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

5 / 10

5. Which of the below are valid Isolations Levels?

choose 2

Random Scatter

Rollback Read

Serializable

Read Committed

6 / 10

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

True

False

7 / 10

7. The SQL standard specifies three isolation levels?

False

True

8 / 10

8. Which parameters sets the database default isolation level?

default_transaction_isolation

default_isolation_level

transaction_isolation_level

active_transaction_isolation

9 / 10

9. non-repeatable read anomaly occurs when?

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.

A transaction reads one and the same row twice, another transaction modifies this row between these reads issue a rollback.

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

clog

view

heap

dump

2 / 10

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

xmax

xmin

xtime

xid

3 / 10

3. UPDATE can be regarded as which 2 separate operations?

INSERT

MERGE

DELETE

COMMIT

4 / 10

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

True

False

5 / 10

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

False

True

6 / 10

6. CLOG contains how many bits for each transaction?

7 / 10

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

pg_current_xact_id()

pg_current_id()

pg_current_xmin_id()

pg_current_commit_id()

8 / 10

8. The page Special Space is located at the start of the page with highest address

True

False

9 / 10

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

True

False

10 / 10

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

archive log

commit log

transaction log

redo log

Your score is

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