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 3 databases exist directly after cluster initialization?

choose 3 options

sysaux

template1

template0

postgres

2 / 20

2. What is a schema?

The name used to refer to a super user account

Namespace that store all objects of a database

A memory area used to cache data from LRU chains

This is the same as a user in Postgres

3 / 20

3. 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

4 / 20

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

True

False

5 / 20

5. Which fork is specific for unlogged tables?

visiblilty map

Main fork

free space map

Initialization fork

6 / 20

6. To understand each other, a client and a server must use one and the same interfacing protocol?

False

True

7 / 20

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

True

False

8 / 20

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

Choose 2 option

Instance

Quorum

Postgres Server

Aurora

9 / 20

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

Access Path

Directory Path

Search Path

Schema Path

10 / 20

10. Users should not modify the template0 database

True

False

11 / 20

11. Tablespaces are used to define physical data layout?

True

False

12 / 20

12. What 3 files/forks as a minimum make up a table on disk?

table map

free space map

Main fork

visiblilty map

13 / 20

13. Files are logically split into pages?

True

False

14 / 20

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

pginit

postman

postgres

init

15 / 20

15. What is the purpose of the visibility map?

provides an audit trail for the database

shows referential relationships for tables

provides the data decryption key

shows a page to be vacuumed or frozen

16 / 20

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

True

False

17 / 20

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

False

True

18 / 20

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

choose 3

tables

sequences

indexes

triggers

19 / 20

19. What is the purpose of the template1 database?

a template for all the other databases

regular database that you can use at your discretion

No such database

database used for temporary tables

20 / 20

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

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

True

False

2 / 10

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

True

False

3 / 10

3. Which of the below are valid Isolations Levels?

choose 2

Rollback Read

Read Committed

Random Scatter

Serializable

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

Replace procedural code with declarative one.

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

5 / 10

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

True

False

6 / 10

6. Which parameters sets the database default isolation level?

default_isolation_level

active_transaction_isolation

transaction_isolation_level

default_transaction_isolation

7 / 10

7. The SQL standard specifies three isolation levels?

False

True

8 / 10

8. 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 uncommited data altered by another session

reading data direct from memory using pg_dirt

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

9 / 10

9. 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

10 / 10

10. 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.

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. What does an Item Pointer contain?

choose 3

tuple xid

tuple length

tuple status

tuple offset from the start of the page

2 / 10

2. Indexes values also support multi versioning with several versions of an index value existing at any point in time?

True

False

3 / 10

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

True

False

4 / 10

4. Page free space can often become fragmented?

True

False

5 / 10

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

True

False

6 / 10

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

Each pointer uses 8 bytes

stored in PGDATA/itemptr directory

Also know as the pages table of contents

Each pointer uses 4 bytes

7 / 10

7. Each page has a layer that usually consists of?

choose 2

page header

undo segment

free space

flashback block

8 / 10

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

pagesize

pageheadinfo

pagedetect

pageinspect

9 / 10

9. CLOG files are stored in which directory?

PGDATA/pg_commit

PGDATA/clog

PGDATA/pg_clog

PGDATA/pg_xact

10 / 10

10. If a transaction is read only which kind of Transaction ID is it allocated?

temporary XID

magic XID

heap XID

virtual XID

Your score is

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