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

Users should not modify the template0 database

False

True

2 / 20

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

GROW

BAKE

BREAD

TOAST

3 / 20

A single Postgres Instance can server only one database?

True

False

4 / 20

Each tablespaces can only be assigned for use by one database

True

False

5 / 20

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

PGCORE

PGDATA

PGBASE

PGTIPS

6 / 20

What command is used to create the Postgres cluster?

CreatePGC

CreateCluster

Initialize

StartNewPG

7 / 20

The information_schema schema provides information on Postgres release notes?

False

True

8 / 20

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

False

True

9 / 20

A schema can belong to more than one database?

True

False

10 / 20

To understand each other, a client and a server must use one and the same interfacing protocol?

True

False

11 / 20

Who is the Author of the Postgres 14 Internals book?

Paul Sammy

Egor Rogov

Dan Brown

Sam Altman

12 / 20

Postgres server spawns a new backend session for each connection?

True

False

13 / 20

pg_catalog schema is used to store system catalog tables?

False

True

14 / 20

Which of the below objects can be referred to as relations?

choose 3

triggers

indexes

tables

sequences

15 / 20

Which fork contains the actual table data?

visiblilty map

Main fork

table map

free space map

16 / 20

Which fork is specific for unlogged tables?

Main fork

free space map

Initialization fork

visiblilty map

17 / 20

What is the point of the pg_global tablespace?

stores temporary tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

stores WAL logs used for global replication

stores user tables that are common to the whole cluster

18 / 20

Postgres by default has built in connection pooling abilities?

True

False

19 / 20

Which of below are predefined schemas?

choose 3

pg_temp

information_schema

pg_schema

pg_toast

20 / 20

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

pg_tblspc

pg_tabspace

pg_symlinks

pg_tablespace

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

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 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 once and modifies this row and commits the change.

2 / 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.

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

Apply explicit locks

3 / 10

Which of the below would best describe a dirty read?

reading data direct from memory using pg_dirt

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

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

4 / 10

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

False

True

5 / 10

What is the default Isolation Level?

Read Uncommitted

Read Committed

Serializable

Repeatable Read

6 / 10

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

True

False

7 / 10

A phantom read anomaly occurs when?

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.

A transactions inserts a null value into a not null columns 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 adds some other rows satisfying this condition and commits.

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?

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

10 / 10

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

False

True

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?

transaction log

redo log

commit log

archive log

2 / 10

CLOG Pages are never cached in memory?

False

True

3 / 10

Page free space can often become fragmented?

True

False

4 / 10

To identify different versions of one and the same row, PostgreSQL marks each of them with which two value?

xmas

xmin

xmax

xid

5 / 10

status of a subtransaction is written into CLOG?

False

True

6 / 10

Postgres table physical data files are always cross compatible across platforms?

True

False

7 / 10

Information about subtransactions is stored under?

PGDATA/subtrans

PGDATA/pg_subtrans

PGDATA/pg_xid

PGDATA/pg_min

8 / 10

Which 2 items does a Virtual XID consist of?

sequential number

checksum

xmin

backend process ID

9 / 10

In Postgres, tables are often referred to as which of the below?

clog

heap

dump

view

10 / 10

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

True

False

Your score is

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