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

True

False

2 / 20

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

False

True

3 / 20

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

vacuum space map

wal space map

used space map

free space map

4 / 20

4. Tablespaces are used to define physical data layout?

False

True

5 / 20

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

Sysasm Catalog

Sys Catalog

System Catalog

Sysaux Catalog

6 / 20

6. What is the purpose of the public schema?

restricted schema for postgres internal usage only

schema used for heterogeneous replication

default schema for user objects

no such schema

7 / 20

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

choose 2

pg_tablespace

pg_temp

pg_global

pg_default

8 / 20

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

True

False

9 / 20

9. Postgres uses a thread based process model?

True

False

10 / 20

10. How many files or forks on disk will a 10Mb table with no index have?

11 / 20

11. Which of below are predefined schemas?

choose 3

pg_toast

pg_temp

pg_schema

information_schema

12 / 20

12. Files are logically split into pages?

False

True

13 / 20

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

obj

oid#

obj#

oid

14 / 20

14. What is the purpose of the template0 database?

Useful for creating development schemas

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

Useful for Postgres support Services to debug issues

No such database

15 / 20

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

True

False

16 / 20

16. Users should not modify the template0 database

True

False

17 / 20

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

True

False

18 / 20

18. Which fork is specific for unlogged tables?

Main fork

visiblilty map

free space map

Initialization fork

19 / 20

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

False

True

20 / 20

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

pg_system

pg_catalog

pg_class

pg_tables

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

Rollback Read

Read Committed

Serializable

Random Scatter

2 / 10

2. A phantom read anomaly occurs when?

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

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.

3 / 10

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

True

False

4 / 10

4. Which parameters sets the database default isolation level?

transaction_isolation_level

default_transaction_isolation

active_transaction_isolation

default_isolation_level

5 / 10

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

False

True

6 / 10

6. 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

Issues a rollback after the commit to satisfy repeatable read.

Replace procedural code with declarative one.

Apply explicit locks

7 / 10

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

SOC2

HIPPA

SAFE

ACID

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 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.

9 / 10

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

True

False

10 / 10

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

True

False

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. Information about subtransactions is stored under?

PGDATA/pg_subtrans

PGDATA/subtrans

PGDATA/pg_min

PGDATA/pg_xid

2 / 10

2. Page free space can often become fragmented?

True

False

3 / 10

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

xmin

backend process ID

sequential number

checksum

4 / 10

4. The page header is located in the highest address?

False

True

5 / 10

5. CLOG contains how many bits for each transaction?

6 / 10

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

view

heap

dump

clog

7 / 10

7. If a transaction aborts, all page changes are reverted(rolled back) in place?

True

False

8 / 10

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

pg_current_commit_id()

pg_current_xact_id()

pg_current_xmin_id()

pg_current_id()

9 / 10

9. CLOG Pages are never cached in memory?

False

True

10 / 10

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

True

False

Your score is

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