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 the template0 database?

No such 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

2 / 20

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

Access Path

Directory Path

Search Path

Schema Path

3 / 20

Which of below are predefined schemas?

choose 2

postgres

pg_catalog

public

system

4 / 20

Postgres by default has built in connection pooling abilities?

False

True

5 / 20

The default Page size is 2k?

False

True

6 / 20

Which 3 databases exist directly after cluster initialization?

choose 3 options

sysaux

template0

postgres

template1

7 / 20

Which fork keeps track of available space within pages?

vacuum space map

free space map

wal space map

used space map

8 / 20

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

Sysasm Catalog

Sys Catalog

System Catalog

Sysaux Catalog

9 / 20

Each Database has its own System Catalog?

False

True

10 / 20

Which fork contains the actual table data?

Main fork

free space map

visiblilty map

table map

11 / 20

What is the point of the pg_global tablespace?

stores system catalog objects that are common to the whole cluster

stores user tables that are common to the whole cluster

stores temporary tables that are common to the whole cluster

stores WAL logs used for global replication

12 / 20

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

13 / 20

A schema can belong to more than one database?

True

False

14 / 20

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

pg_system

pg_catalog

pg_class

pg_tables

15 / 20

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

False

True

16 / 20

The information_schema schema provides information on Postgres release notes?

False

True

17 / 20

What is another name for the postgres process?

postmaster

postmanager

masterprocess

aurora

18 / 20

What is the name of the mechanism used to store a row bigger than a page size?

TOAST

GROW

BAKE

BREAD

19 / 20

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

False

True

20 / 20

To be able to restore data consistency, Postgres maintains

undo segments (UNDO)

write-ahead log (WAL)

rollback segments (RBS)

online redo logs (ORL)

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

Which parameters sets the database default isolation level?

default_transaction_isolation

active_transaction_isolation

default_isolation_level

transaction_isolation_level

2 / 10

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

True

False

3 / 10

which of the below statements will start a transaction as Read Repeatable?

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

4 / 10

non-repeatable read anomaly occurs when?

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.

A transaction reads one and the same row once and modifies this row and commits the change.

5 / 10

Which of the below are valid Isolations Levels?

choose 2

Random Scatter

Read Committed

Rollback Read

Serializable

6 / 10

What is the default Isolation Level?

Read Committed

Read Uncommitted

Repeatable Read

Serializable

7 / 10

The SQL standard specifies three isolation levels?

False

True

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 of the below would best describe a dirty read?

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

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

10 / 10

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

Read Uncommitted

Read Committed

Repeatable 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

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

True

False

2 / 10

The page Special Space is located at the start of the page with highest address

False

True

3 / 10

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

INSERT

COMMIT

CREATE

DELETE

4 / 10

The page header stores checksum and the sizes of the other parts of the page?

True

False

5 / 10

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

False

True

6 / 10

A page along with its tuples is read into the buffer cache with compression transformations to enhance cache efficiency?

True

False

7 / 10

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

pg_current_commit_id()

pg_current_id()

pg_current_xmin_id()

pg_current_xact_id()

8 / 10

index row headers like table row headers contain xmin and xmax fields?

False

True

9 / 10

What does an Item Pointer contain?

choose 3

tuple offset from the start of the page

tuple length

tuple xid

tuple status

10 / 10

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

False

True

Your score is

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