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

pg_tblspc

pg_tabspace

pg_symlinks

pg_tablespace

2 / 20

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

False

True

3 / 20

3. Tablespaces are used to define physical data layout?

False

True

4 / 20

4. What is another name for the postgres process?

postmanager

aurora

masterprocess

postmaster

5 / 20

5. What is the purpose of the visibility map?

provides the data decryption key

shows a page to be vacuumed or frozen

provides an audit trail for the database

shows referential relationships for tables

6 / 20

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

False

True

7 / 20

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

choose 2

pg_default

pg_global

pg_temp

pg_tablespace

8 / 20

8. What is the point of the pg_global tablespace?

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

stores user tables that are common to the whole cluster

9 / 20

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

True

False

10 / 20

10. Each Database has its own System Catalog?

False

True

11 / 20

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

Initialize

CreatePGC

StartNewPG

CreateCluster

12 / 20

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

13 / 20

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

oid#

obj#

oid

obj

14 / 20

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

Sysasm Catalog

System Catalog

Sysaux Catalog

Sys Catalog

15 / 20

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

False

True

16 / 20

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

17 / 20

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

True

False

18 / 20

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

False

True

19 / 20

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

PGDATA

PGCORE

PGTIPS

PGBASE

20 / 20

20. What is a schema?

A memory area used to cache data from LRU chains

This is the same as a user in Postgres

Namespace that store all objects of a database

The name used to refer to a super user account

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

True

False

2 / 10

2. A phantom read anomaly occurs when?

The same transactions issues a commit, then a rollback to restore data to its original value

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.

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.

3 / 10

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

False

True

4 / 10

4. 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;

5 / 10

5. The SQL standard specifies three isolation levels?

True

False

6 / 10

6. Which of the below would best describe a dirty read?

reading data direct from memory using pg_dirt

a session being able to see uncommited data altered by another session

a session being able to see commited data altered by another session

reading the data directly from file using a text editor such as vi or notepad

7 / 10

7. Which parameters sets the database default isolation level?

transaction_isolation_level

active_transaction_isolation

default_transaction_isolation

default_isolation_level

8 / 10

8. Which of the below are valid Isolations Levels?

choose 2

Rollback Read

Serializable

Read Committed

Random Scatter

9 / 10

9. non-repeatable read anomaly occurs when?

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.

A transaction reads one and the same row twice, another transaction modifies this row between these reads issue a rollback.

10 / 10

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

Read Committed

Repeatable Read

Serializable

Read Uncommitted

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

True

False

2 / 10

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

False

True

3 / 10

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

True

False

4 / 10

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

True

False

5 / 10

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

temporary XID

magic XID

heap XID

virtual XID

6 / 10

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

pageinspect

pagedetect

pagesize

pageheadinfo

7 / 10

7. indexes do not use row versioning?

False

True

8 / 10

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

False

True

9 / 10

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

stored in PGDATA/itemptr directory

Each pointer uses 4 bytes

Each pointer uses 8 bytes

Also know as the pages table of contents

10 / 10

10. CLOG Pages are never cached in memory?

True

False

Your score is

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