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

Sys Catalog

System Catalog

Sysaux Catalog

Sysasm Catalog

2 / 20

2. pg_catalog schema is used to store system catalog tables?

False

True

3 / 20

3. Which of below are predefined schemas?

choose 2

system

pg_catalog

postgres

public

4 / 20

4. What is the purpose of the public schema?

no such schema

default schema for user objects

restricted schema for postgres internal usage only

schema used for heterogeneous replication

5 / 20

5. Tablespaces are used to define physical data layout?

True

False

6 / 20

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

pg_tabspace

pg_symlinks

pg_tablespace

pg_tblspc

7 / 20

7. What is the purpose of the template0 database?

Useful for Postgres support Services to debug issues

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

Useful for creating development schemas

No such database

8 / 20

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

False

True

9 / 20

9. Postgres uses a thread based process model?

False

True

10 / 20

10. How many rows in a page does Postgres aim to have before considering TOAST?

11 / 20

11. TOAST tables reside in a seperate schema?

False

True

12 / 20

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

1GB

5MB

1MB

5GB

13 / 20

13. What is a schema?

Namespace that store all objects of a database

The name used to refer to a super user account

A memory area used to cache data from LRU chains

This is the same as a user in Postgres

14 / 20

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

Choose 2 option

Aurora

Postgres Server

Instance

Quorum

15 / 20

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

choose 3

indexes

sequences

tables

triggers

16 / 20

16. What column in system catalogs servers as the Primary Key

obj#

oid

oid#

obj

17 / 20

17. A single Postgres Instance can server only one database?

True

False

18 / 20

18. How does Postgres know which schema to use if not specified?

Search Path

Access Path

Directory Path

Schema Path

19 / 20

19. Which 3 databases exist directly after cluster initialization?

choose 3 options

sysaux

template0

template1

postgres

20 / 20

20. Postgres server spawns a new backend session for each connection?

False

True

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

True

False

2 / 10

2. 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 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 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

3 / 10

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

choose 3

Serializable

Repeatable Read

Read Uncommitted

Read Committed

4 / 10

4. The SQL standard specifies three isolation levels?

False

True

5 / 10

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

Serializable

Read Uncommitted

Read Committed

Repeatable Read

6 / 10

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

ACID

HIPPA

SAFE

SOC2

7 / 10

7. Which parameters sets the database default isolation level?

transaction_isolation_level

default_transaction_isolation

active_transaction_isolation

default_isolation_level

8 / 10

8. Which of the below would best describe a dirty read?

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

reading data direct from memory using pg_dirt

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

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

9 / 10

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

True

False

10 / 10

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 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.

A transaction reads one and the same row once, another transaction modifies this row between these reads and commits the change.

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. Each page has a layer that usually consists of?

choose 2

free space

page header

undo segment

flashback block

2 / 10

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

xmin

xmax

xmas

xid

3 / 10

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

False

True

4 / 10

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

False

True

5 / 10

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

virtual XID

heap XID

magic XID

temporary XID

6 / 10

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

redo log

commit log

archive log

transaction log

7 / 10

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

False

True

8 / 10

8. What does an Item Pointer contain?

choose 3

tuple length

tuple offset from the start of the page

tuple xid

tuple status

9 / 10

9. Tuples can also be referred to as columns?

False

True

10 / 10

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

xmin

xtime

xmax

xid

Your score is

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