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 3 files/forks as a minimum make up a table on disk?

table map

Main fork

visiblilty map

free space map

2 / 20

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

True

False

3 / 20

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

False

True

4 / 20

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

obj#

oid

oid#

obj

5 / 20

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

Initialize

StartNewPG

CreatePGC

CreateCluster

6 / 20

6. Files are logically split into pages?

False

True

7 / 20

7. What is another name for the postgres process?

postmanager

masterprocess

postmaster

aurora

8 / 20

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

9 / 20

9. Users should not modify the template0 database

True

False

10 / 20

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

False

True

11 / 20

11. What is a schema?

A memory area used to cache data from LRU chains

The name used to refer to a super user account

This is the same as a user in Postgres

Namespace that store all objects of a database

12 / 20

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

Schema Path

Directory Path

Search Path

Access Path

13 / 20

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

False

True

14 / 20

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

BAKE

BREAD

TOAST

GROW

15 / 20

15. What is the point of the pg_global tablespace?

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

stores WAL logs used for global replication

16 / 20

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

Sys Catalog

Sysasm Catalog

Sysaux Catalog

System Catalog

17 / 20

17. What is the purpose of the visibility map?

provides the data decryption key

provides an audit trail for the database

shows referential relationships for tables

shows a page to be vacuumed or frozen

18 / 20

18. TOAST tables reside in a seperate schema?

True

False

19 / 20

19. System Catalog tables begin with which prefix?

sys_

pg_

dba_

cat_

20 / 20

20. Postgres by default has built in connection pooling abilities?

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

True

False

2 / 10

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

False

True

3 / 10

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

SAFE

ACID

SOC2

HIPPA

4 / 10

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

Read Uncommitted

Serializable

Repeatable Read

Read Committed

5 / 10

5. The SQL standard specifies three isolation levels?

True

False

6 / 10

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

Select more than 1 answer below:

Replace procedural code with declarative one.

Apply explicit locks

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

7 / 10

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

True

False

8 / 10

8. Which of the below are valid Isolations Levels?

choose 2

Rollback Read

Serializable

Random Scatter

Read Committed

9 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

10 / 10

10. 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 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

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.

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

xmax

xmas

xmin

xid

2 / 10

2. Which 2 items does a Virtual XID consist of?

sequential number

xmin

backend process ID

checksum

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

pg_current_xmin_id()

pg_current_id()

pg_current_commit_id()

pg_current_xact_id()

5 / 10

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

pagesize

pageheadinfo

pageinspect

pagedetect

6 / 10

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

False

True

7 / 10

7. CLOG Pages are never cached in memory?

False

True

8 / 10

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

False

True

9 / 10

9. CLOG files are stored in which directory?

PGDATA/pg_xact

PGDATA/pg_commit

PGDATA/clog

PGDATA/pg_clog

10 / 10

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

temporary XID

magic XID

heap XID

virtual XID

Your score is

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