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 rows in a page does Postgres aim to have before considering TOAST?

2 / 20

2. Which 3 databases exist directly after cluster initialization?

choose 3 options

template1

sysaux

postgres

template0

3 / 20

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

Dan Brown

Paul Sammy

Egor Rogov

Sam Altman

4 / 20

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

False

True

5 / 20

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

True

False

6 / 20

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

Access Path

Schema Path

Search Path

Directory Path

7 / 20

7. What is the purpose of the visibility map?

shows referential relationships for tables

shows a page to be vacuumed or frozen

provides the data decryption key

provides an audit trail for the database

8 / 20

8. Which of below are predefined schemas?

choose 3

pg_toast

pg_temp

pg_schema

information_schema

9 / 20

9. TOAST tables reside in a seperate schema?

True

False

10 / 20

10. What is a schema?

This is the same as a user in Postgres

A memory area used to cache data from LRU chains

The name used to refer to a super user account

Namespace that store all objects of a database

11 / 20

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

BAKE

TOAST

GROW

BREAD

12 / 20

12. System Catalog tables begin with which prefix?

pg_

sys_

cat_

dba_

13 / 20

13. What is another name for the postgres process?

postmanager

masterprocess

aurora

postmaster

14 / 20

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

free space map

used space map

vacuum space map

wal space map

15 / 20

15. Which of the below objects can be referred to as relations?

choose 3

tables

triggers

indexes

sequences

16 / 20

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

choose 2

pg_tablespace

pg_default

pg_temp

pg_global

17 / 20

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

True

False

18 / 20

18. 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

19 / 20

19. What is the purpose of the template0 database?

Useful for Postgres support Services to debug issues

Useful for creating development schemas

No such database

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

20 / 20

20. The default Page size is 2k?

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. The SQL standard specifies three isolation levels?

False

True

2 / 10

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

True

False

3 / 10

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

False

True

4 / 10

4. 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 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 issue a rollback.

A transaction reads one and the same row twice, another transaction modifies this row between these reads and commits the change.

5 / 10

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

True

False

6 / 10

6. Snapshot isolation is preferred but increases the number of required locks?

False

True

7 / 10

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

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

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

8 / 10

8. Which parameters sets the database default isolation level?

default_transaction_isolation

transaction_isolation_level

active_transaction_isolation

default_isolation_level

9 / 10

9. 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.

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

Apply explicit locks

10 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

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

False

True

2 / 10

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

True

False

3 / 10

3. What does an Item Pointer contain?

choose 3

tuple status

tuple xid

tuple length

tuple offset from the start of the page

4 / 10

4. Postgres table physical data files are always cross compatible across platforms?

True

False

5 / 10

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

False

True

6 / 10

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

False

True

7 / 10

7. Tuples can also be referred to as columns?

True

False

8 / 10

8. Which of the below are true about a Pages Item Pointer?

Also know as the pages table of contents

Each pointer uses 4 bytes

Each pointer uses 8 bytes

stored in PGDATA/itemptr directory

9 / 10

9. status of a subtransaction is written into CLOG?

False

True

10 / 10

10. CLOG files are stored in which directory?

PGDATA/pg_commit

PGDATA/pg_clog

PGDATA/clog

PGDATA/pg_xact

Your score is

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