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

TOAST tables reside in a seperate schema?

False

True

2 / 20

What is the purpose of the postgres database?

No such database

regular database that you can use at your discretion

a template for all the other database

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

3 / 20

What is another name for the postgres process?

postmaster

masterprocess

aurora

postmanager

4 / 20

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

choose 2

pg_tablespace

pg_global

pg_default

pg_temp

5 / 20

Postgres uses a thread based process model?

False

True

6 / 20

What is the purpose of autovacuum?

Performs a backup of WAL logs

Deletes old logs and traces on disk

Rebuilds indexes with b level greater than 2

Removes stale data from tables and indexes

7 / 20

What is the purpose of wal writer?

writes WAL entries to disk

executes checkpoints

flushes dirty pages to disk.

collects usage statistics for the instance.

8 / 20

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

Choose 2 option

Quorum

Postgres Server

Aurora

Instance

9 / 20

Each Database has its own System Catalog?

True

False

10 / 20

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

free space map

table map

visiblilty map

Main fork

11 / 20

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

False

True

12 / 20

The default Page size is 2k?

True

False

13 / 20

Which of below are predefined schemas?

choose 2

system

pg_catalog

postgres

public

14 / 20

Which fork contains the actual table data?

free space map

Main fork

visiblilty map

table map

15 / 20

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

choose 3

triggers

indexes

tables

sequences

16 / 20

Postgres by default has built in connection pooling abilities?

False

True

17 / 20

Which of below are predefined schemas?

choose 3

pg_temp

pg_toast

pg_schema

information_schema

18 / 20

A schema can belong to more than one database?

False

True

19 / 20

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

pg_tables

pg_catalog

pg_system

pg_class

20 / 20

Which 3 databases exist directly after cluster initialization?

choose 3 options

template0

template1

sysaux

postgres

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

The SQL standard specifies three isolation levels?

True

False

2 / 10

A phantom read anomaly occurs when?

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 also queries this same data.

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.

3 / 10

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

SOC2

SAFE

HIPPA

ACID

4 / 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 issue a rollback.

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.

5 / 10

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

True

False

6 / 10

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

choose 3

Repeatable Read

Read Committed

Read Uncommitted

Serializable

7 / 10

What is the default Isolation Level?

Read Uncommitted

Repeatable Read

Serializable

Read Committed

8 / 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;

9 / 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

Issues a rollback after the commit to satisfy repeatable read.

Use a single SQL operator

Replace procedural code with declarative one.

10 / 10

Which of the below would best describe a dirty read?

reading the data directly from file using a text editor such as vi or notepad

reading data direct from memory using pg_dirt

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

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

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

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

False

True

2 / 10

Information about subtransactions is stored under?

PGDATA/pg_subtrans

PGDATA/subtrans

PGDATA/pg_xid

PGDATA/pg_min

3 / 10

What does an Item Pointer contain?

choose 3

tuple xid

tuple offset from the start of the page

tuple status

tuple length

4 / 10

psql provides a special mode that allows you to continue a transaction after a failure?

True

False

5 / 10

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

True

False

6 / 10

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

False

True

7 / 10

Page free space can often become fragmented?

False

True

8 / 10

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

xmax

xmas

xmin

xid

9 / 10

indexes do not use row versioning?

False

True

10 / 10

Which function can we use to find the current transaction ID?

pg_current_id()

pg_current_xact_id()

pg_current_xmin_id()

pg_current_commit_id()

Your score is

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