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. Which fork keeps track of available space within pages?

vacuum space map

used space map

wal space map

free space map

2 / 20

2. Each Database has its own System Catalog?

False

True

3 / 20

3. Users should not modify the template0 database

True

False

4 / 20

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

True

False

5 / 20

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

PGDATA

PGTIPS

PGBASE

PGCORE

6 / 20

6. Which 3 databases exist directly after cluster initialization?

choose 3 options

sysaux

template0

template1

postgres

7 / 20

7. pg_catalog schema is used to store system catalog tables?

False

True

8 / 20

8. What is the purpose of wal writer?

flushes dirty pages to disk.

executes checkpoints

collects usage statistics for the instance.

writes WAL entries to disk

9 / 20

9. TOAST tables reside in a seperate schema?

True

False

10 / 20

10. What is a schema?

Namespace that store all objects of a database

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

11 / 20

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

False

True

12 / 20

12. Postgres by default has built in connection pooling abilities?

True

False

13 / 20

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

Access Path

Search Path

Schema Path

Directory Path

14 / 20

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

False

True

15 / 20

15. Files are logically split into pages?

False

True

16 / 20

16. The default Page size is 2k?

False

True

17 / 20

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

True

False

18 / 20

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

19 / 20

19. System Catalog tables begin with which prefix?

pg_

dba_

cat_

sys_

20 / 20

20. Postgres uses a thread based process model?

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

Read Uncommitted

Read Committed

Serializable

Repeatable Read

2 / 10

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

True

False

3 / 10

3. 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

Replace procedural code with declarative one.

Issues a rollback after the commit to satisfy repeatable read.

4 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

5 / 10

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

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

reading data direct from memory using pg_dirt

6 / 10

6. What is the default Isolation Level?

Serializable

Read Committed

Read Uncommitted

Repeatable Read

7 / 10

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

True

False

8 / 10

8. Which of the below are valid Isolations Levels?

choose 2

Rollback Read

Serializable

Random Scatter

Read Committed

9 / 10

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

True

False

10 / 10

10. 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 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.

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. Tuples can also be referred to as columns?

False

True

2 / 10

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

dump

view

clog

heap

3 / 10

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

True

False

4 / 10

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

False

True

5 / 10

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

Each pointer uses 8 bytes

Also know as the pages table of contents

Each pointer uses 4 bytes

stored in PGDATA/itemptr directory

6 / 10

6. What does an Item Pointer contain?

choose 3

tuple length

tuple offset from the start of the page

tuple status

tuple xid

7 / 10

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

True

False

8 / 10

8. status of a subtransaction is written into CLOG?

False

True

9 / 10

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

False

True

10 / 10

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

pagesize

pagedetect

pageinspect

pageheadinfo

Your score is

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