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 is specific for unlogged tables?

Initialization fork

visiblilty map

free space map

Main fork

2 / 20

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

Dan Brown

Sam Altman

Egor Rogov

Paul Sammy

3 / 20

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

write-ahead log (WAL)

undo segments (UNDO)

rollback segments (RBS)

online redo logs (ORL)

4 / 20

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

True

False

5 / 20

5. Tablespaces are used to define physical data layout?

True

False

6 / 20

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

True

False

7 / 20

7. The default Page size is 2k?

False

True

8 / 20

8. Postgres uses a thread based process model?

False

True

9 / 20

9. TOAST tables reside in a seperate schema?

False

True

10 / 20

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

choose 2

pg_default

pg_tablespace

pg_global

pg_temp

11 / 20

11. Which 3 databases exist directly after cluster initialization?

choose 3 options

template1

template0

postgres

sysaux

12 / 20

12. What is another name for the postgres process?

postmanager

aurora

postmaster

masterprocess

13 / 20

13. Which fork contains the actual table data?

table map

visiblilty map

free space map

Main fork

14 / 20

14. What is the name of the catalog that stores metadata for all cluster objects?

Sysaux Catalog

Sys Catalog

System Catalog

Sysasm Catalog

15 / 20

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

True

False

16 / 20

16. What is the purpose of the postgres 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

a template for all the other database

17 / 20

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

obj#

oid

oid#

obj

18 / 20

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

False

True

19 / 20

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

PGTIPS

PGDATA

PGBASE

PGCORE

20 / 20

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

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 of the below would best describe a dirty read?

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

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

2 / 10

2. Which of the below are valid Isolations Levels?

choose 2

Random Scatter

Read Committed

Rollback Read

Serializable

3 / 10

3. 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.

Issues a rollback after the commit to satisfy repeatable read.

Apply explicit locks

Use a single SQL operator

4 / 10

4. What is the default Isolation Level?

Read Uncommitted

Read Committed

Repeatable Read

Serializable

5 / 10

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

True

False

6 / 10

6. 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.

The same transactions issues a commit, then a rollback to restore data to its original value

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.

7 / 10

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

Repeatable Read

Read Uncommitted

Serializable

Read Committed

8 / 10

8. The SQL standard specifies three isolation levels?

True

False

9 / 10

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

False

True

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 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 twice, 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.

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 of the below are true about a Pages Item Pointer?

Each pointer uses 4 bytes

Also know as the pages table of contents

stored in PGDATA/itemptr directory

Each pointer uses 8 bytes

2 / 10

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

False

True

3 / 10

3. Tuples can also be referred to as columns?

True

False

4 / 10

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

clog

dump

view

heap

5 / 10

5. The page header stores checksum and the sizes of the other parts of the page?

True

False

6 / 10

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

redo log

commit log

archive log

transaction log

7 / 10

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

temporary XID

heap XID

magic XID

virtual XID

8 / 10

8. What does an Item Pointer contain?

choose 3

tuple length

tuple status

tuple offset from the start of the page

tuple xid

9 / 10

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

xtime

xmin

xid

xmax

10 / 10

10. CLOG Pages are never cached in memory?

True

False

Your score is

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