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

True

False

2 / 20

2. System Catalog tables begin with which prefix?

dba_

cat_

sys_

pg_

3 / 20

3. What is the purpose of autovacuum?

Performs a backup of WAL logs

Removes stale data from tables and indexes

Deletes old logs and traces on disk

Rebuilds indexes with b level greater than 2

4 / 20

4. Each Database has its own System Catalog?

True

False

5 / 20

5. It is the postmasters job to listener for incoming connections?

False

True

6 / 20

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

postman

postgres

pginit

init

7 / 20

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

False

True

8 / 20

8. What is the purpose of the template0 database?

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

No such database

Useful for creating development schemas

Useful for Postgres support Services to debug issues

9 / 20

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

vacuum space map

free space map

wal space map

used space map

10 / 20

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

oid

obj

obj#

oid#

11 / 20

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

pg_catalog

pg_class

pg_tables

pg_system

12 / 20

12. Users should not modify the template0 database

False

True

13 / 20

13. TOAST tables reside in a seperate schema?

True

False

14 / 20

14. What is the purpose of the visibility map?

shows a page to be vacuumed or frozen

shows referential relationships for tables

provides the data decryption key

provides an audit trail for the database

15 / 20

15. Which 3 databases exist directly after cluster initialization?

choose 3 options

template1

sysaux

template0

postgres

16 / 20

16. Which of below are predefined schemas?

choose 3

pg_temp

pg_schema

information_schema

pg_toast

17 / 20

17. What is the purpose of wal writer?

flushes dirty pages to disk.

writes WAL entries to disk

collects usage statistics for the instance.

executes checkpoints

18 / 20

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

False

True

19 / 20

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

False

True

20 / 20

20. 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

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 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.

2 / 10

2. Which parameters sets the database default isolation level?

active_transaction_isolation

transaction_isolation_level

default_transaction_isolation

default_isolation_level

3 / 10

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

True

False

4 / 10

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

False

True

5 / 10

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

Repeatable Read

Read Uncommitted

Serializable

Read Committed

6 / 10

6. The SQL standard specifies three isolation levels?

False

True

7 / 10

7. 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

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 data direct from memory using pg_dirt

8 / 10

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

Select more than 1 answer below:

Issues a rollback after the commit to satisfy repeatable read.

Use a single SQL operator

Apply explicit locks

Replace procedural code with declarative one.

9 / 10

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

choose 3

Repeatable Read

Serializable

Read Uncommitted

Read Committed

10 / 10

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

SOC2

ACID

SAFE

HIPPA

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

pagedetect

pageheadinfo

pageinspect

pagesize

2 / 10

2. Page free space can often become fragmented?

False

True

3 / 10

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

False

True

4 / 10

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

COMMIT

CREATE

DELETE

INSERT

5 / 10

5. Tuples can also be referred to as columns?

True

False

6 / 10

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

archive log

transaction log

redo log

commit log

7 / 10

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

False

True

8 / 10

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

False

True

9 / 10

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

COMMIT

DELETE

INSERT

MERGE

10 / 10

10. indexes do not use row versioning?

True

False

Your score is

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