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

It is the postmasters job to listener for incoming connections?

True

False

2 / 20

What is the purpose of the template1 database?

regular database that you can use at your discretion

No such database

database used for temporary tables

a template for all the other databases

3 / 20

A schema can belong to more than one database?

False

True

4 / 20

Tablespaces are used to define physical data layout?

True

False

5 / 20

Which of below are predefined schemas?

choose 2

pg_catalog

postgres

system

public

6 / 20

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

7 / 20

What is the name of the directory that contains the files related to the Postgres cluster?

PGTIPS

PGCORE

PGBASE

PGDATA

8 / 20

The default Page size is 2k?

False

True

9 / 20

Each tablespaces can only be assigned for use by one database

False

True

10 / 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.

11 / 20

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

TOAST

BREAD

GROW

BAKE

12 / 20

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

True

False

13 / 20

Files are logically split into pages?

True

False

14 / 20

What is the default standard size for a fork file?

1GB

5MB

1MB

5GB

15 / 20

What command is used to create the Postgres cluster?

Initialize

StartNewPG

CreateCluster

CreatePGC

16 / 20

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

Search Path

Directory Path

Access Path

Schema Path

17 / 20

What is the process first launched at server start?

postman

postgres

pginit

init

18 / 20

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

visiblilty map

Main fork

table map

free space map

19 / 20

What is the purpose of the postgres database?

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

regular database that you can use at your discretion

No such database

a template for all the other database

20 / 20

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

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 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

2 / 10

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

True

False

3 / 10

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

True

False

4 / 10

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

True

False

5 / 10

What is the default Isolation Level?

Read Committed

Repeatable Read

Serializable

Read Uncommitted

6 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

7 / 10

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

False

True

8 / 10

What are some of database features we can use to avoid a non repeatable read?

Select more than 1 answer below:

Replace procedural code with declarative one.

Apply explicit locks

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

9 / 10

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

SOC2

HIPPA

SAFE

ACID

10 / 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, 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 and commits the change.

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

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

commit log

transaction log

archive log

redo log

2 / 10

CLOG files are stored in which directory?

PGDATA/pg_clog

PGDATA/pg_commit

PGDATA/clog

PGDATA/pg_xact

3 / 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()

4 / 10

Each page has a layer that usually consists of?

choose 2

flashback block

page header

undo segment

free space

5 / 10

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

True

False

6 / 10

UPDATE can be regarded as which 2 separate operations?

INSERT

DELETE

COMMIT

MERGE

7 / 10

CLOG contains how many bits for each transaction?

8 / 10

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

False

True

9 / 10

Information about subtransactions is stored under?

PGDATA/pg_subtrans

PGDATA/pg_xid

PGDATA/subtrans

PGDATA/pg_min

10 / 10

at any one time Postgres can have several versions of a row?

False

True

Your score is

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