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 column in system catalogs servers as the Primary Key

oid#

obj#

obj

oid

2 / 20

2. What is a schema?

The name used to refer to a super user account

Namespace that store all objects of a database

A memory area used to cache data from LRU chains

This is the same as a user in Postgres

3 / 20

3. What is the process first launched at server start?

postman

pginit

init

postgres

4 / 20

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

True

False

5 / 20

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

choose 2

pg_global

pg_default

pg_tablespace

pg_temp

6 / 20

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

True

False

7 / 20

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

PGCORE

PGTIPS

PGBASE

PGDATA

8 / 20

8. 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

9 / 20

9. Files are logically split into pages?

True

False

10 / 20

10. Users should not modify the template0 database

False

True

11 / 20

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

TOAST

BAKE

GROW

BREAD

12 / 20

12. Who is the Author of the Postgres 14 Internals book?

Dan Brown

Paul Sammy

Egor Rogov

Sam Altman

13 / 20

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

False

True

14 / 20

14. Tablespaces are used to define physical data layout?

False

True

15 / 20

15. Which fork contains the actual table data?

Main fork

table map

visiblilty map

free space map

16 / 20

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

pg_symlinks

pg_tblspc

pg_tablespace

pg_tabspace

17 / 20

17. What is the purpose of the template0 database?

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

Useful for creating development schemas

No such database

Useful for Postgres support Services to debug issues

18 / 20

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

True

False

19 / 20

19. What is the point of the pg_global tablespace?

stores system catalog objects that are common to the whole cluster

stores temporary tables that are common to the whole cluster

stores user tables that are common to the whole cluster

stores WAL logs used for global replication

20 / 20

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

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

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

True

False

2 / 10

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

True

False

3 / 10

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

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

4 / 10

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

choose 3

Serializable

Read Uncommitted

Repeatable Read

Read Committed

5 / 10

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

Serializable

Repeatable Read

Read Committed

Read Uncommitted

6 / 10

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

False

True

7 / 10

7. 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 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 issue a rollback.

8 / 10

8. Which parameters sets the database default isolation level?

transaction_isolation_level

default_transaction_isolation

default_isolation_level

active_transaction_isolation

9 / 10

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

True

False

10 / 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

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

INSERT

COMMIT

DELETE

MERGE

2 / 10

2. The page header stores checksum and the sizes of the other parts of the page?

False

True

3 / 10

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

pg_current_id()

pg_current_commit_id()

pg_current_xact_id()

pg_current_xmin_id()

4 / 10

4. What does an Item Pointer contain?

choose 3

tuple xid

tuple offset from the start of the page

tuple status

tuple length

5 / 10

5. CLOG Pages are never cached in memory?

False

True

6 / 10

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

False

True

7 / 10

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

True

False

8 / 10

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

DELETE

COMMIT

INSERT

CREATE

9 / 10

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

commit log

archive log

redo log

transaction log

10 / 10

10. CLOG files are stored in which directory?

PGDATA/pg_commit

PGDATA/pg_xact

PGDATA/pg_clog

PGDATA/clog

Your score is

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