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 the purpose of the postgres database?

restoring data from a logical backup or creating a database with a different encoding

a template for all the other database

regular database that you can use at your discretion

No such database

2 / 20

2. Which fork is specific for unlogged tables?

visiblilty map

Initialization fork

free space map

Main fork

3 / 20

3. What is the purpose of autovacuum?

Deletes old logs and traces on disk

Performs a backup of WAL logs

Removes stale data from tables and indexes

Rebuilds indexes with b level greater than 2

4 / 20

4. System Catalog tables begin with which prefix?

sys_

cat_

dba_

pg_

5 / 20

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

6 / 20

6. What is another name for the postgres process?

masterprocess

postmanager

postmaster

aurora

7 / 20

7. What is a schema?

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

Namespace that store all objects of a database

8 / 20

8. What is the purpose of the visibility map?

provides an audit trail for the database

shows a page to be vacuumed or frozen

shows referential relationships for tables

provides the data decryption key

9 / 20

9. TOAST tables reside in a seperate schema?

False

True

10 / 20

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

oid#

obj#

oid

obj

11 / 20

11. Users should not modify the template0 database

False

True

12 / 20

12. What is the purpose of the template1 database?

No such database

regular database that you can use at your discretion

database used for temporary tables

a template for all the other databases

13 / 20

13. Which of below are predefined schemas?

choose 2

pg_catalog

system

public

postgres

14 / 20

14. A schema can belong to more than one database?

True

False

15 / 20

15. Which fork contains the actual table data?

Main fork

visiblilty map

free space map

table map

16 / 20

16. Postgres uses a thread based process model?

True

False

17 / 20

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

True

False

18 / 20

18. What is the point of the pg_global tablespace?

stores temporary tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

stores user tables that are common to the whole cluster

stores WAL logs used for global replication

19 / 20

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

Directory Path

Schema Path

Search Path

Access Path

20 / 20

20. Which 3 databases exist directly after cluster initialization?

choose 3 options

template0

postgres

sysaux

template1

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

choose 3

Read Committed

Read Uncommitted

Repeatable Read

Serializable

2 / 10

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

Read Uncommitted

Repeatable Read

Serializable

Read Committed

3 / 10

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

HIPPA

SOC2

ACID

SAFE

4 / 10

4. What is the default Isolation Level?

Serializable

Read Uncommitted

Read Committed

Repeatable Read

5 / 10

5. A phantom read anomaly occurs when?

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 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.

6 / 10

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

True

False

7 / 10

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

False

True

8 / 10

8. non-repeatable read anomaly occurs when?

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 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 twice, another transaction modifies this row between these reads and commits the change.

9 / 10

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

False

True

10 / 10

10. Which of the below are valid Isolations Levels?

choose 2

Read Committed

Random Scatter

Rollback Read

Serializable

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

False

True

2 / 10

2. Tuples can also be referred to as columns?

False

True

3 / 10

3. CLOG Pages are never cached in memory?

True

False

4 / 10

4. Information about subtransactions is stored under?

PGDATA/pg_min

PGDATA/pg_xid

PGDATA/subtrans

PGDATA/pg_subtrans

5 / 10

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

True

False

6 / 10

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

True

False

7 / 10

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

pg_current_commit_id()

pg_current_xmin_id()

pg_current_id()

pg_current_xact_id()

8 / 10

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

xmin

backend process ID

checksum

sequential number

9 / 10

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

view

dump

heap

clog

10 / 10

10. UPDATE can be regarded as which 2 separate operations?

MERGE

COMMIT

DELETE

INSERT

Your score is

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