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. Postgres by default has built in connection pooling abilities?

True

False

2 / 20

2. Which of below are predefined schemas?

choose 2

public

pg_catalog

postgres

system

3 / 20

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

CreateCluster

Initialize

StartNewPG

CreatePGC

4 / 20

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

pg_tabspace

pg_tablespace

pg_symlinks

pg_tblspc

5 / 20

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

5GB

5MB

1GB

1MB

6 / 20

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

False

True

7 / 20

7. Tablespaces are used to define physical data layout?

False

True

8 / 20

8. What is the name of the system catalog table for relations?

pg_system

pg_class

pg_catalog

pg_tables

9 / 20

9. What is the point of the pg_global tablespace?

stores WAL logs used for global replication

stores temporary tables that are common to the whole cluster

stores user tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

10 / 20

10. What is the purpose of the public schema?

default schema for user objects

schema used for heterogeneous replication

restricted schema for postgres internal usage only

no such schema

11 / 20

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

False

True

12 / 20

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

postgres

postman

pginit

init

13 / 20

13. Which fork contains the actual table data?

table map

free space map

Main fork

visiblilty map

14 / 20

14. The information_schema schema provides information on Postgres release notes?

False

True

15 / 20

15. 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

16 / 20

16. Which of below are predefined schemas?

choose 3

pg_toast

information_schema

pg_schema

pg_temp

17 / 20

17. Which fork is specific for unlogged tables?

visiblilty map

free space map

Main fork

Initialization fork

18 / 20

18. Files are logically split into pages?

True

False

19 / 20

19. What is the purpose of autovacuum?

Rebuilds indexes with b level greater than 2

Deletes old logs and traces on disk

Performs a backup of WAL logs

Removes stale data from tables and indexes

20 / 20

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

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

CREATE EXTENSTION REPEATABLE_READ;

2 / 10

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

Select more than 1 answer below:

Apply explicit locks

Issues a rollback after the commit to satisfy repeatable read.

Use a single SQL operator

Replace procedural code with declarative one.

3 / 10

3. What is the default Isolation Level?

Repeatable Read

Read Uncommitted

Read Committed

Serializable

4 / 10

4. 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 issue a rollback.

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

5 / 10

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

Repeatable Read

Serializable

Read Uncommitted

Read Committed

6 / 10

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

False

True

7 / 10

7. A phantom read anomaly occurs when?

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 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

8 / 10

8. Lost updates are forbidden by the standard at all isolation levels?

True

False

9 / 10

9. The SQL standard specifies three isolation levels?

True

False

10 / 10

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

HIPPA

ACID

SOC2

SAFE

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 aborts, all page changes are reverted(rolled back) in place?

True

False

2 / 10

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

pagedetect

pageheadinfo

pagesize

pageinspect

3 / 10

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

False

True

4 / 10

4. CLOG files are stored in which directory?

PGDATA/pg_clog

PGDATA/pg_commit

PGDATA/clog

PGDATA/pg_xact

5 / 10

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

DELETE

INSERT

CREATE

COMMIT

6 / 10

6. at any one time Postgres can have several versions of a row?

False

True

7 / 10

7. indexes do not use row versioning?

True

False

8 / 10

8. The page Special Space is located at the start of the page with highest address

True

False

9 / 10

9. CLOG Pages are never cached in memory?

True

False

10 / 10

10. Information about subtransactions is stored under?

PGDATA/pg_min

PGDATA/pg_subtrans

PGDATA/pg_xid

PGDATA/subtrans

Your score is

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