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

Who is the Author of the Postgres 14 Internals book?

Dan Brown

Sam Altman

Egor Rogov

Paul Sammy

2 / 20

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

False

True

3 / 20

What is the default standard size for a fork file?

1GB

5MB

5GB

1MB

4 / 20

What column in system catalogs servers as the Primary Key

oid#

obj#

oid

obj

5 / 20

Which of below are predefined schemas?

choose 3

pg_toast

pg_temp

pg_schema

information_schema

6 / 20

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

Sysaux Catalog

System Catalog

Sys Catalog

Sysasm Catalog

7 / 20

Which of below are predefined schemas?

choose 2

pg_catalog

system

postgres

public

8 / 20

TOAST tables reside in a seperate schema?

True

False

9 / 20

A single Postgres Instance can server only one database?

True

False

10 / 20

Which fork is specific for unlogged tables?

Main fork

visiblilty map

Initialization fork

free space map

11 / 20

Tablespaces are used to define physical data layout?

False

True

12 / 20

What is the purpose of wal writer?

flushes dirty pages to disk.

writes WAL entries to disk

executes checkpoints

collects usage statistics for the instance.

13 / 20

What is a schema?

This is the same as a user in Postgres

The name used to refer to a super user account

A memory area used to cache data from LRU chains

Namespace that store all objects of a database

14 / 20

What is another name for the postgres process?

masterprocess

postmanager

postmaster

aurora

15 / 20

Which fork keeps track of available space within pages?

wal space map

vacuum space map

used space map

free space map

16 / 20

What command is used to create the Postgres cluster?

CreateCluster

StartNewPG

Initialize

CreatePGC

17 / 20

System Catalog tables begin with which prefix?

dba_

pg_

sys_

cat_

18 / 20

What is the purpose of the template0 database?

Useful for creating development schemas

Useful for Postgres support Services to debug issues

No such database

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

19 / 20

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

BAKE

BREAD

TOAST

GROW

20 / 20

Each Database has its own System Catalog?

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

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 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.

2 / 10

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

SOC2

SAFE

HIPPA

ACID

3 / 10

Which parameters sets the database default isolation level?

default_isolation_level

default_transaction_isolation

active_transaction_isolation

transaction_isolation_level

4 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

5 / 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 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

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 also queries this same data.

6 / 10

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

False

True

7 / 10

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

Select more than 1 answer below:

Apply explicit locks

Use a single SQL operator

Replace procedural code with declarative one.

Issues a rollback after the commit to satisfy repeatable read.

8 / 10

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

True

False

9 / 10

What is the default Isolation Level?

Repeatable Read

Serializable

Read Committed

Read Uncommitted

10 / 10

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

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

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

transaction log

archive log

commit log

redo log

2 / 10

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

True

False

3 / 10

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

False

True

4 / 10

Information about subtransactions is stored under?

PGDATA/pg_xid

PGDATA/pg_subtrans

PGDATA/pg_min

PGDATA/subtrans

5 / 10

Which 2 items does a Virtual XID consist of?

backend process ID

checksum

xmin

sequential number

6 / 10

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

xid

xmax

xtime

xmin

7 / 10

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

False

True

8 / 10

CLOG Pages are never cached in memory?

False

True

9 / 10

Tuples can also be referred to as columns?

False

True

10 / 10

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

True

False

Your score is

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