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 name of the catalog that stores metadata for all cluster objects?

Sys Catalog

Sysasm Catalog

Sysaux Catalog

System Catalog

2 / 20

2. What is another name for the postgres process?

postmanager

aurora

masterprocess

postmaster

3 / 20

3. What is the purpose of wal writer?

writes WAL entries to disk

collects usage statistics for the instance.

flushes dirty pages to disk.

executes checkpoints

4 / 20

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

postgres

postman

pginit

init

5 / 20

5. What is a schema?

A memory area used to cache data from LRU chains

Namespace that store all objects of a database

This is the same as a user in Postgres

The name used to refer to a super user account

6 / 20

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

Choose 2 option

Instance

Quorum

Aurora

Postgres Server

7 / 20

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

PGTIPS

PGBASE

PGCORE

PGDATA

8 / 20

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

True

False

9 / 20

9. To be able to restore data consistency, Postgres maintains

write-ahead log (WAL)

online redo logs (ORL)

rollback segments (RBS)

undo segments (UNDO)

10 / 20

10. What is the point of the pg_global tablespace?

stores user tables that are common to the whole cluster

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

11 / 20

11. The default Page size is 2k?

True

False

12 / 20

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

wal space map

vacuum space map

used space map

free space map

13 / 20

13. Each Database has its own System Catalog?

True

False

14 / 20

14. What is the purpose of the template1 database?

regular database that you can use at your discretion

a template for all the other databases

No such database

database used for temporary tables

15 / 20

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

True

False

16 / 20

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

17 / 20

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

Schema Path

Access Path

Search Path

Directory Path

18 / 20

18. What is the purpose of the postgres database?

a template for all the other database

No such database

regular database that you can use at your discretion

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

19 / 20

19. What is the purpose of the template0 database?

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

Useful for creating development schemas

Useful for Postgres support Services to debug issues

No such database

20 / 20

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

True

False

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 would best describe a dirty read?

reading data direct from memory using pg_dirt

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

2 / 10

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

False

True

3 / 10

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

False

True

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

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

Replace procedural code with declarative one.

5 / 10

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

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

6 / 10

6. non-repeatable read anomaly occurs when?

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, another transaction modifies this row between these reads and commits the change.

A transaction reads one and the same row once and modifies this row and commits the change.

7 / 10

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

False

True

8 / 10

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

Serializable

Read Committed

Repeatable Read

Read Uncommitted

9 / 10

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

SAFE

ACID

SOC2

HIPPA

10 / 10

10. Which parameters sets the database default isolation level?

transaction_isolation_level

default_transaction_isolation

active_transaction_isolation

default_isolation_level

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

pg_current_id()

pg_current_commit_id()

pg_current_xact_id()

pg_current_xmin_id()

2 / 10

2. What does an Item Pointer contain?

choose 3

tuple length

tuple xid

tuple status

tuple offset from the start of the page

3 / 10

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

True

False

4 / 10

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

False

True

5 / 10

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

xid

xmin

xmax

xtime

6 / 10

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

pageheadinfo

pageinspect

pagedetect

pagesize

7 / 10

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

redo log

archive log

transaction log

commit log

8 / 10

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

False

True

9 / 10

9. status of a subtransaction is written into CLOG?

True

False

10 / 10

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

False

True

Your score is

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