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

table map

free space map

visiblilty map

Main fork

3 / 20

Which fork is specific for unlogged tables?

Initialization fork

free space map

Main fork

visiblilty map

4 / 20

To be able to restore data consistency, Postgres maintains

online redo logs (ORL)

write-ahead log (WAL)

undo segments (UNDO)

rollback segments (RBS)

5 / 20

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

choose 3

triggers

sequences

tables

indexes

6 / 20

Postgres server spawns a new backend session for each connection?

True

False

7 / 20

Files are logically split into pages?

True

False

8 / 20

Which of below are predefined schemas?

choose 3

pg_schema

pg_temp

pg_toast

information_schema

9 / 20

When PostgreSQL is running what can it be referred to as?

Choose 2 option

Aurora

Quorum

Postgres Server

Instance

10 / 20

What is the purpose of the postgres database?

regular database that you can use at your discretion

a template for all the other database

No such database

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

11 / 20

Each tablespaces can only be assigned for use by one database

False

True

12 / 20

What is the purpose of wal writer?

executes checkpoints

flushes dirty pages to disk.

collects usage statistics for the instance.

writes WAL entries to disk

13 / 20

System Catalog tables begin with which prefix?

pg_

sys_

cat_

dba_

14 / 20

What is the purpose of autovacuum?

Performs a backup of WAL logs

Deletes old logs and traces on disk

Removes stale data from tables and indexes

Rebuilds indexes with b level greater than 2

15 / 20

Users should not modify the template0 database

True

False

16 / 20

The information_schema schema provides information on Postgres release notes?

True

False

17 / 20

What is the purpose of the public schema?

no such schema

restricted schema for postgres internal usage only

default schema for user objects

schema used for heterogeneous replication

18 / 20

Tablespaces are used to define physical data layout?

False

True

19 / 20

What is the process first launched at server start?

init

postgres

postman

pginit

20 / 20

Postgres by default has built in connection pooling abilities?

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

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

False

True

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.

Issues a rollback after the commit to satisfy repeatable read.

Use a single SQL operator

Apply explicit locks

3 / 10

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

HIPPA

SOC2

ACID

SAFE

4 / 10

non-repeatable read anomaly occurs when?

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 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.

5 / 10

Which of the below are valid Isolations Levels?

choose 2

Serializable

Rollback Read

Random Scatter

Read Committed

6 / 10

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

Read Uncommitted

Read Committed

Serializable

Repeatable Read

7 / 10

The SQL standard specifies three isolation levels?

False

True

8 / 10

What is the default Isolation Level?

Serializable

Repeatable Read

Read Committed

Read Uncommitted

9 / 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

10 / 10

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

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

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

True

False

2 / 10

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

False

True

3 / 10

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

True

False

4 / 10

index row headers like table row headers contain xmin and xmax fields?

True

False

5 / 10

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

stored in PGDATA/itemptr directory

Each pointer uses 8 bytes

Each pointer uses 4 bytes

Also know as the pages table of contents

6 / 10

When a row is created, its xmin value is set to the transaction ID of which command?

CREATE

DELETE

INSERT

COMMIT

7 / 10

Page free space can often become fragmented?

False

True

8 / 10

CLOG contains how many bits for each transaction?

9 / 10

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

True

False

10 / 10

Indexes values also support multi versioning with several versions of an index value existing at any point in time?

True

False

Your score is

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