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 purpose of the template0 database?

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

Useful for Postgres support Services to debug issues

Useful for creating development schemas

No such database

2 / 20

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

Dan Brown

Paul Sammy

Egor Rogov

Sam Altman

3 / 20

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

False

True

4 / 20

4. Tablespaces can be used to segregate data based on performance needs?

False

True

5 / 20

5. Tablespaces are used to define physical data layout?

False

True

6 / 20

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

True

False

7 / 20

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

False

True

8 / 20

8. To understand each other, a client and a server must use one and the same interfacing protocol?

False

True

9 / 20

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

GROW

BREAD

BAKE

TOAST

10 / 20

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

False

True

11 / 20

11. Which of below are predefined schemas?

choose 2

postgres

public

system

pg_catalog

12 / 20

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

False

True

13 / 20

13. Which fork contains the actual table data?

visiblilty map

table map

Main fork

free space map

14 / 20

14. Which 3 databases exist directly after cluster initialization?

choose 3 options

postgres

template1

sysaux

template0

15 / 20

15. To be able to restore data consistency, Postgres maintains

online redo logs (ORL)

undo segments (UNDO)

rollback segments (RBS)

write-ahead log (WAL)

16 / 20

16. Files are logically split into pages?

True

False

17 / 20

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

False

True

18 / 20

18. What is the point of the pg_global tablespace?

stores user tables that are common to the whole cluster

stores WAL logs used for global replication

stores system catalog objects that are common to the whole cluster

stores temporary tables that are common to the whole cluster

19 / 20

19. The default Page size is 2k?

False

True

20 / 20

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.

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

True

False

2 / 10

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

choose 3

Serializable

Read Committed

Read Uncommitted

Repeatable Read

3 / 10

3. The SQL standard specifies three isolation levels?

True

False

4 / 10

4. Which parameters sets the database default isolation level?

transaction_isolation_level

default_isolation_level

active_transaction_isolation

default_transaction_isolation

5 / 10

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

True

False

6 / 10

6. What is the default Isolation Level?

Read Uncommitted

Read Committed

Serializable

Repeatable Read

7 / 10

7. What are some of database features we can use to avoid a non repeatable read?

Select more than 1 answer below:

Apply explicit locks

Use a single SQL operator

Replace procedural code with declarative one.

Issues a rollback after the commit to satisfy repeatable read.

8 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

9 / 10

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

False

True

10 / 10

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 twice, another transaction modifies this row between these reads 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. Which of the below are true about a Pages Item Pointer?

Also know as the pages table of contents

Each pointer uses 8 bytes

Each pointer uses 4 bytes

stored in PGDATA/itemptr directory

2 / 10

2. status of a subtransaction is written into CLOG?

False

True

3 / 10

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

True

False

4 / 10

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

True

False

5 / 10

5. A page along with its tuples is read into the buffer cache with compression transformations to enhance cache efficiency?

False

True

6 / 10

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

False

True

7 / 10

7. Page header sizes can be easily displayed using the <choose from answers> extension

pagesize

pageheadinfo

pagedetect

pageinspect

8 / 10

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

False

True

9 / 10

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

True

False

10 / 10

10. Information about subtransactions is stored under?

PGDATA/pg_xid

PGDATA/subtrans

PGDATA/pg_min

PGDATA/pg_subtrans

Your score is

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