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

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

2 / 20

What is the point of the pg_global tablespace?

stores WAL logs used for global replication

stores temporary tables that are common to the whole cluster

stores user tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

3 / 20

Some System Catalog tables are common to all databases in the cluster?

True

False

4 / 20

What command is used to create the Postgres cluster?

Initialize

CreatePGC

CreateCluster

StartNewPG

5 / 20

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

GROW

TOAST

BREAD

BAKE

6 / 20

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

pg_catalog

pg_class

pg_system

pg_tables

7 / 20

If we create a new tablespace which directory will symbolic links be created from?

pg_tabspace

pg_tablespace

pg_symlinks

pg_tblspc

8 / 20

What is the purpose of the public schema?

default schema for user objects

restricted schema for postgres internal usage only

schema used for heterogeneous replication

no such schema

9 / 20

Postgres by default has built in connection pooling abilities?

True

False

10 / 20

What is the process first launched at server start?

pginit

postgres

init

postman

11 / 20

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

No such database

Useful for Postgres support Services to debug issues

12 / 20

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

choose 2

pg_tablespace

pg_default

pg_global

pg_temp

13 / 20

What is the purpose of the visibility map?

provides the data decryption key

provides an audit trail for the database

shows referential relationships for tables

shows a page to be vacuumed or frozen

14 / 20

A schema can belong to more than one database?

True

False

15 / 20

Which of below are predefined schemas?

choose 3

pg_temp

pg_schema

pg_toast

information_schema

16 / 20

What is the purpose of the postgres database?

a template for all the other database

regular database that you can use at your discretion

No such database

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

17 / 20

Files are logically split into pages?

True

False

18 / 20

Postgres server spawns a new backend session for each connection?

True

False

19 / 20

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

free space map

table map

visiblilty map

Main fork

20 / 20

What column in system catalogs servers as the Primary Key

oid

obj#

oid#

obj

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

Serializable

Read Committed

Read Uncommitted

Repeatable Read

2 / 10

non-repeatable read anomaly occurs when?

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 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 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.

3 / 10

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

False

True

4 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

5 / 10

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

SOC2

SAFE

HIPPA

ACID

6 / 10

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

choose 3

Serializable

Read Uncommitted

Read Committed

Repeatable Read

7 / 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 uncommited 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 commited data altered by another session

8 / 10

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

Apply explicit locks

Replace procedural code with declarative one.

Issues a rollback after the commit to satisfy repeatable read.

9 / 10

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

True

False

10 / 10

The SQL standard specifies three isolation levels?

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

status of a subtransaction is written into CLOG?

False

True

2 / 10

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

True

False

3 / 10

Page free space can often become fragmented?

False

True

4 / 10

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

False

True

5 / 10

Which 2 of the below represent transaction IDs used for row versioning?

xmax

xid

xmin

xtime

6 / 10

Tuples can also be referred to as columns?

False

True

7 / 10

When a transaction is committed Postgres uses a special <replace with answer> structure?

commit log

redo log

transaction log

archive log

8 / 10

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

Each pointer uses 8 bytes

Each pointer uses 4 bytes

stored in PGDATA/itemptr directory

Also know as the pages table of contents

9 / 10

UPDATE can be regarded as which 2 separate operations?

DELETE

COMMIT

INSERT

MERGE

10 / 10

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

False

True

Your score is

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