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

False

True

2 / 20

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

Dan Brown

Sam Altman

Paul Sammy

Egor Rogov

3 / 20

3. Which of below are predefined schemas?

choose 2

system

public

pg_catalog

postgres

4 / 20

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

False

True

5 / 20

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

postman

pginit

postgres

init

6 / 20

6. Postgres uses a thread based process model?

False

True

7 / 20

7. 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

8 / 20

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

oid#

oid

obj#

obj

9 / 20

9. What is the purpose of wal writer?

writes WAL entries to disk

flushes dirty pages to disk.

collects usage statistics for the instance.

executes checkpoints

10 / 20

10. What is the name of the system catalog table for relations?

pg_catalog

pg_system

pg_tables

pg_class

11 / 20

11. TOAST tables reside in a seperate schema?

True

False

12 / 20

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

PGTIPS

PGCORE

PGBASE

PGDATA

13 / 20

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

choose 3

indexes

triggers

sequences

tables

14 / 20

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

Choose 2 option

Quorum

Aurora

Postgres Server

Instance

15 / 20

15. The default Page size is 2k?

False

True

16 / 20

16. What is another name for the postgres process?

postmaster

masterprocess

postmanager

aurora

17 / 20

17. What is the point of the pg_global tablespace?

stores WAL logs used for global replication

stores system catalog objects that are common to the whole cluster

stores temporary tables that are common to the whole cluster

stores user tables that are common to the whole cluster

18 / 20

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

False

True

19 / 20

19. Tablespaces are used to define physical data layout?

True

False

20 / 20

20. Users should not modify the template0 database

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. Which of the below are valid Isolations Levels?

choose 2

Serializable

Read Committed

Rollback Read

Random Scatter

2 / 10

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

False

True

3 / 10

3. The SQL standard specifies three isolation levels?

False

True

4 / 10

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

Select more than 1 answer below:

Use a single SQL operator

Apply explicit locks

Replace procedural code with declarative one.

Issues a rollback after the commit to satisfy repeatable read.

5 / 10

5. 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 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.

6 / 10

6. A phantom read anomaly occurs when?

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

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 transaction executes two identical queries returning a set of rows that satisfy a particular condition, while another transaction also queries this same data.

A transactions inserts a null value into a not null columns and commits

7 / 10

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

False

True

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

Repeatable Read

Serializable

Read Committed

Read Uncommitted

10 / 10

10. Which parameters sets the database default isolation level?

default_transaction_isolation

default_isolation_level

transaction_isolation_level

active_transaction_isolation

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 function can we use to find the current transaction ID?

pg_current_id()

pg_current_commit_id()

pg_current_xmin_id()

pg_current_xact_id()

2 / 10

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

checksum

xmin

sequential number

backend process ID

3 / 10

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

False

True

4 / 10

4. CLOG contains how many bits for each transaction?

5 / 10

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

True

False

6 / 10

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

True

False

7 / 10

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

False

True

8 / 10

8. CLOG files are stored in which directory?

PGDATA/pg_commit

PGDATA/pg_xact

PGDATA/pg_clog

PGDATA/clog

9 / 10

9. indexes do not use row versioning?

False

True

10 / 10

10. When a row is created, its xmin value is set to the transaction ID of which command?

CREATE

COMMIT

DELETE

INSERT

Your score is

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