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

False

True

2 / 20

2. Which fork is specific for unlogged tables?

free space map

visiblilty map

Main fork

Initialization fork

3 / 20

3. What is the point of the pg_global tablespace?

stores WAL logs used for global replication

stores user tables that are common to the whole cluster

stores temporary tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

4 / 20

4. What is the purpose of the template1 database?

regular database that you can use at your discretion

No such database

database used for temporary tables

a template for all the other databases

5 / 20

5. Postgres uses a thread based process model?

True

False

6 / 20

6. What is the purpose of wal writer?

collects usage statistics for the instance.

flushes dirty pages to disk.

writes WAL entries to disk

executes checkpoints

7 / 20

7. Users should not modify the template0 database

True

False

8 / 20

8. Files are logically split into pages?

False

True

9 / 20

9. What is the purpose of the postgres database?

a template for all the other database

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

No such database

regular database that you can use at your discretion

10 / 20

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

True

False

11 / 20

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

True

False

12 / 20

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

CreateCluster

Initialize

CreatePGC

StartNewPG

13 / 20

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

pg_tablespace

pg_tabspace

pg_tblspc

pg_symlinks

14 / 20

14. How many files or forks on disk will a 10Mb table with no index have?

15 / 20

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

postman

pginit

postgres

init

16 / 20

16. System Catalog tables begin with which prefix?

pg_

sys_

dba_

cat_

17 / 20

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

18 / 20

18. What is the purpose of the visibility map?

shows a page to be vacuumed or frozen

provides an audit trail for the database

provides the data decryption key

shows referential relationships for tables

19 / 20

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

True

False

20 / 20

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

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. Which parameters sets the database default isolation level?

default_isolation_level

default_transaction_isolation

active_transaction_isolation

transaction_isolation_level

2 / 10

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

True

False

3 / 10

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

Repeatable Read

Read Committed

Read Uncommitted

Serializable

4 / 10

4. 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.

5 / 10

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

HIPPA

SOC2

ACID

SAFE

6 / 10

6. The SQL standard specifies three isolation levels?

False

True

7 / 10

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

True

False

8 / 10

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

Select more than 1 answer below:

Issues a rollback after the commit to satisfy repeatable read.

Use a single SQL operator

Apply explicit locks

Replace procedural code with declarative one.

9 / 10

9. What is the default Isolation Level?

Read Uncommitted

Repeatable Read

Read Committed

Serializable

10 / 10

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

False

True

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?

COMMIT

DELETE

MERGE

INSERT

2 / 10

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

True

False

3 / 10

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

xmax

xmin

xid

xtime

4 / 10

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

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. Which of the below are true about a Pages Item Pointer?

Each pointer uses 4 bytes

Also know as the pages table of contents

Each pointer uses 8 bytes

stored in PGDATA/itemptr directory

7 / 10

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

pg_current_commit_id()

pg_current_xact_id()

pg_current_xmin_id()

pg_current_id()

8 / 10

8. virtual IDs exist only in PGDATA/pg_vxid when not cached?

True

False

9 / 10

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

True

False

10 / 10

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

choose 2

free space

undo segment

page header

flashback block

Your score is

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