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 a schema?

The name used to refer to a super user account

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

2 / 20

2. How many rows in a page does Postgres aim to have before considering TOAST?

3 / 20

3. What is another name for the postgres process?

aurora

postmanager

masterprocess

postmaster

4 / 20

4. What is the default standard size for a fork file?

1GB

1MB

5MB

5GB

5 / 20

5. Which of below are predefined schemas?

choose 2

public

system

pg_catalog

postgres

6 / 20

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

True

False

7 / 20

7. Which of below are predefined schemas?

choose 3

information_schema

pg_schema

pg_toast

pg_temp

8 / 20

8. What is the point of the pg_global tablespace?

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

stores user tables that are common to the whole cluster

9 / 20

9. Users should not modify the template0 database

True

False

10 / 20

10. Postgres server spawns a new backend session for each connection?

False

True

11 / 20

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

PGBASE

PGDATA

PGCORE

PGTIPS

12 / 20

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

True

False

13 / 20

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

visiblilty map

Main fork

free space map

table map

14 / 20

14. What is the purpose of autovacuum?

Performs a backup of WAL logs

Rebuilds indexes with b level greater than 2

Deletes old logs and traces on disk

Removes stale data from tables and indexes

15 / 20

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

choose 3

sequences

tables

indexes

triggers

16 / 20

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

write-ahead log (WAL)

online redo logs (ORL)

undo segments (UNDO)

rollback segments (RBS)

17 / 20

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

False

True

18 / 20

18. Each Database has its own System Catalog?

False

True

19 / 20

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

used space map

free space map

vacuum space map

wal space map

20 / 20

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

obj

oid

oid#

obj#

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. 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.

3 / 10

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

False

True

4 / 10

4. Based on Snapshot Isolation use of MVCC which of the below are permitted?

choose 3

Read Uncommitted

Read Committed

Repeatable Read

Serializable

5 / 10

5. What are some of database features we can use to avoid a non repeatable read?

Select more than 1 answer below:

Apply explicit locks

Issues a rollback after the commit to satisfy repeatable read.

Replace procedural code with declarative one.

Use a single SQL operator

6 / 10

6. What is the default Isolation Level?

Read Committed

Serializable

Repeatable Read

Read Uncommitted

7 / 10

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

True

False

8 / 10

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

True

False

9 / 10

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

reading data direct from memory using pg_dirt

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

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

10 / 10

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

ACID

SOC2

SAFE

HIPPA

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

True

False

2 / 10

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

virtual XID

temporary XID

heap XID

magic XID

3 / 10

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

pg_current_xmin_id()

pg_current_id()

pg_current_commit_id()

pg_current_xact_id()

4 / 10

4. Tuples can also be referred to as columns?

False

True

5 / 10

5. Which 2 items does a Virtual XID consist of?

checksum

sequential number

xmin

backend process ID

6 / 10

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

xmax

xmin

xtime

xid

7 / 10

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

False

True

8 / 10

8. status of a subtransaction is written into CLOG?

False

True

9 / 10

9. What does an Item Pointer contain?

choose 3

tuple xid

tuple length

tuple offset from the start of the page

tuple status

10 / 10

10. indexes do not use row versioning?

False

True

Your score is

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