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

What is the purpose of wal writer?

collects usage statistics for the instance.

executes checkpoints

writes WAL entries to disk

flushes dirty pages to disk.

2 / 20

What column in system catalogs servers as the Primary Key

obj#

oid#

oid

obj

3 / 20

Which fork contains the actual table data?

Main fork

free space map

visiblilty map

table map

4 / 20

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

visiblilty map

table map

free space map

Main fork

5 / 20

Postgres server spawns a new backend session for each connection?

False

True

6 / 20

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

Sysaux Catalog

Sysasm Catalog

System Catalog

Sys Catalog

7 / 20

What is the purpose of the template0 database?

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

Useful for Postgres support Services to debug issues

Useful for creating development schemas

No such database

8 / 20

A schema can belong to more than one database?

True

False

9 / 20

Which fork is specific for unlogged tables?

visiblilty map

free space map

Initialization fork

Main fork

10 / 20

pg_catalog schema is used to store system catalog tables?

False

True

11 / 20

What is a schema?

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

This is the same as a user in Postgres

12 / 20

Users should not modify the template0 database

True

False

13 / 20

The default Page size is 2k?

True

False

14 / 20

A single Postgres Instance can server only one database?

False

True

15 / 20

Which of below are predefined schemas?

choose 3

pg_toast

pg_temp

pg_schema

information_schema

16 / 20

Postgres uses a thread based process model?

False

True

17 / 20

The information_schema schema provides information on Postgres release notes?

False

True

18 / 20

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

choose 2

pg_temp

pg_tablespace

pg_global

pg_default

19 / 20

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

True

False

20 / 20

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

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

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

False

True

2 / 10

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

True

False

3 / 10

What is the default Isolation Level?

Read Committed

Repeatable Read

Read Uncommitted

Serializable

4 / 10

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

False

True

5 / 10

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 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 issue a rollback.

6 / 10

Which of the below would best describe a dirty read?

reading data direct from memory using pg_dirt

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

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

7 / 10

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

SAFE

HIPPA

ACID

SOC2

8 / 10

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 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

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.

9 / 10

Which parameters sets the database default isolation level?

default_isolation_level

active_transaction_isolation

default_transaction_isolation

transaction_isolation_level

10 / 10

Which of the below are valid Isolations Levels?

choose 2

Random Scatter

Serializable

Rollback Read

Read Committed

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

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

False

True

2 / 10

The page header is located in the highest address?

False

True

3 / 10

Page header sizes can be easily displayed using the <choose from answers> extension

pageinspect

pagedetect

pageheadinfo

pagesize

4 / 10

Each page has a layer that usually consists of?

choose 2

undo segment

page header

free space

flashback block

5 / 10

CLOG files are stored in which directory?

PGDATA/pg_commit

PGDATA/pg_xact

PGDATA/clog

PGDATA/pg_clog

6 / 10

Tuples can also be referred to as columns?

False

True

7 / 10

UPDATE can be regarded as which 2 separate operations?

MERGE

DELETE

COMMIT

INSERT

8 / 10

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

True

False

9 / 10

Information about subtransactions is stored under?

PGDATA/pg_xid

PGDATA/pg_subtrans

PGDATA/pg_min

PGDATA/subtrans

10 / 10

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

True

False

Your score is

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