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

1. A Postgres cluster consists of 2 or more physical servers accessing one Postgres Instance?

False

True

2 / 20

2. Users should not modify the template0 database

True

False

3 / 20

3. Each tablespaces can only be assigned for use by one database

True

False

4 / 20

4. A schema can belong to more than one database?

False

True

5 / 20

5. What is the purpose of the template0 database?

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

Useful for creating development schemas

6 / 20

6. What is the purpose of autovacuum?

Removes stale data from tables and indexes

Rebuilds indexes with b level greater than 2

Performs a backup of WAL logs

Deletes old logs and traces on disk

7 / 20

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

choose 2

pg_tablespace

pg_global

pg_default

pg_temp

8 / 20

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

PGTIPS

PGDATA

PGBASE

PGCORE

9 / 20

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

pg_tabspace

pg_symlinks

pg_tblspc

pg_tablespace

10 / 20

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

False

True

11 / 20

11. What command is used to create the Postgres cluster?

StartNewPG

CreateCluster

Initialize

CreatePGC

12 / 20

12. What is the default standard size for a fork file?

5GB

1MB

5MB

1GB

13 / 20

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

Choose 2 option

Quorum

Aurora

Instance

Postgres Server

14 / 20

14. It is the postmasters job to listener for incoming connections?

True

False

15 / 20

15. Each Database has its own System Catalog?

True

False

16 / 20

16. Which of below are predefined schemas?

choose 3

information_schema

pg_toast

pg_temp

pg_schema

17 / 20

17. Which fork keeps track of available space within pages?

free space map

vacuum space map

wal space map

used space map

18 / 20

18. What is a schema?

Namespace that store all objects of a database

The name used to refer to a super user account

This is the same as a user in Postgres

A memory area used to cache data from LRU chains

19 / 20

19. System Catalog tables begin with which prefix?

pg_

cat_

sys_

dba_

20 / 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

1. 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 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.

A transaction reads one and the same row twice, another transaction modifies this row between these reads issue a rollback.

2 / 10

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

Repeatable Read

Serializable

Read Uncommitted

Read Committed

3 / 10

3. The SQL standard specifies three isolation levels?

False

True

4 / 10

4. Which parameters sets the database default isolation level?

default_isolation_level

transaction_isolation_level

default_transaction_isolation

active_transaction_isolation

5 / 10

5. 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 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

6 / 10

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

False

True

7 / 10

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

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

8 / 10

8. Which of the below are valid Isolations Levels?

choose 2

Read Committed

Serializable

Random Scatter

Rollback Read

9 / 10

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

choose 3

Repeatable Read

Read Uncommitted

Serializable

Read Committed

10 / 10

10. What is the default Isolation Level?

Read Uncommitted

Read Committed

Serializable

Repeatable Read

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

1. If a transaction is read only which kind of Transaction ID is it allocated?

virtual XID

heap XID

temporary XID

magic XID

2 / 10

2. CLOG contains how many bits for each transaction?

3 / 10

3. 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

4 / 10

4. CLOG Pages are never cached in memory?

False

True

5 / 10

5. The page header is located in the highest address?

False

True

6 / 10

6. Each page has a layer that usually consists of?

choose 2

page header

free space

undo segment

flashback block

7 / 10

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

False

True

8 / 10

8. What does an Item Pointer contain?

choose 3

tuple offset from the start of the page

tuple status

tuple length

tuple xid

9 / 10

9. UPDATE can be regarded as which 2 separate operations?

MERGE

DELETE

COMMIT

INSERT

10 / 10

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

dump

heap

clog

view

Your score is

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