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

Which fork contains the actual table data?

table map

free space map

Main fork

visiblilty map

2 / 20

Tablespaces are used to define physical data layout?

False

True

3 / 20

What is the purpose of the template0 database?

No such database

Useful for Postgres support Services to debug issues

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

Useful for creating development schemas

4 / 20

pg_catalog schema is used to store system catalog tables?

False

True

5 / 20

What is the purpose of the public schema?

default schema for user objects

no such schema

schema used for heterogeneous replication

restricted schema for postgres internal usage only

6 / 20

Files are logically split into pages?

True

False

7 / 20

Which fork keeps track of available space within pages?

vacuum space map

used space map

free space map

wal space map

8 / 20

What is the process first launched at server start?

postgres

postman

init

pginit

9 / 20

Which of below are predefined schemas?

choose 3

pg_temp

pg_schema

pg_toast

information_schema

10 / 20

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

choose 2

pg_global

pg_temp

pg_default

pg_tablespace

11 / 20

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

BAKE

TOAST

BREAD

GROW

12 / 20

What is the purpose of autovacuum?

Removes stale data from tables and indexes

Deletes old logs and traces on disk

Rebuilds indexes with b level greater than 2

Performs a backup of WAL logs

13 / 20

What is the default standard size for a fork file?

1MB

5GB

5MB

1GB

14 / 20

To be able to restore data consistency, Postgres maintains

write-ahead log (WAL)

rollback segments (RBS)

online redo logs (ORL)

undo segments (UNDO)

15 / 20

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

16 / 20

TOAST tables reside in a seperate schema?

True

False

17 / 20

It is the postmasters job to listener for incoming connections?

True

False

18 / 20

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

19 / 20

What is the purpose of the template1 database?

a template for all the other databases

regular database that you can use at your discretion

No such database

database used for temporary tables

20 / 20

Each tablespaces can only be assigned for use by one 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

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

choose 3

Read Uncommitted

Read Committed

Serializable

Repeatable Read

2 / 10

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

False

True

3 / 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 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

4 / 10

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

Read Uncommitted

Repeatable Read

Read Committed

Serializable

5 / 10

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

False

True

6 / 10

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

True

False

7 / 10

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

False

True

8 / 10

The SQL standard specifies three isolation levels?

False

True

9 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

10 / 10

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

ACID

HIPPA

SOC2

SAFE

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

CLOG files are stored in which directory?

PGDATA/pg_clog

PGDATA/clog

PGDATA/pg_xact

PGDATA/pg_commit

2 / 10

CLOG contains how many bits for each transaction?

3 / 10

Information about subtransactions is stored under?

PGDATA/pg_xid

PGDATA/pg_min

PGDATA/subtrans

PGDATA/pg_subtrans

4 / 10

Which of the below are true about a Pages Item Pointer?

Also know as the pages table of contents

Each pointer uses 4 bytes

stored in PGDATA/itemptr directory

Each pointer uses 8 bytes

5 / 10

Each page has a layer that usually consists of?

choose 2

undo segment

page header

flashback block

free space

6 / 10

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

False

True

7 / 10

virtual IDs exist only in PGDATA/pg_vxid when not cached?

True

False

8 / 10

indexes do not use row versioning?

True

False

9 / 10

Page free space can often become fragmented?

True

False

10 / 10

What does an Item Pointer contain?

choose 3

tuple xid

tuple length

tuple offset from the start of the page

tuple status

Your score is

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