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 be able to restore data consistency, Postgres maintains

undo segments (UNDO)

rollback segments (RBS)

write-ahead log (WAL)

online redo logs (ORL)

2 / 20

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

True

False

3 / 20

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

CreatePGC

CreateCluster

Initialize

StartNewPG

4 / 20

4. What is the purpose of the public schema?

default schema for user objects

restricted schema for postgres internal usage only

schema used for heterogeneous replication

no such schema

5 / 20

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

1GB

5MB

1MB

5GB

6 / 20

6. When PostgreSQL is running what can it be referred to as?

Choose 2 option

Instance

Aurora

Quorum

Postgres Server

7 / 20

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

TOAST

BREAD

BAKE

GROW

8 / 20

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

True

False

9 / 20

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

False

True

10 / 20

10. What is the purpose of the postgres 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

a template for all the other database

11 / 20

11. Which fork is specific for unlogged tables?

visiblilty map

Initialization fork

free space map

Main fork

12 / 20

12. Which of below are predefined schemas?

choose 3

pg_schema

pg_toast

pg_temp

information_schema

13 / 20

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

PGTIPS

PGBASE

PGCORE

PGDATA

14 / 20

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

False

True

15 / 20

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

oid

obj#

obj

oid#

16 / 20

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

System Catalog

Sys Catalog

Sysaux Catalog

Sysasm Catalog

17 / 20

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

True

False

18 / 20

18. Postgres uses a thread based process model?

True

False

19 / 20

19. The default Page size is 2k?

False

True

20 / 20

20. System Catalog tables begin with which prefix?

pg_

cat_

dba_

sys_

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?

False

True

2 / 10

2. The SQL standard specifies three isolation levels?

True

False

3 / 10

3. 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.

4 / 10

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

False

True

5 / 10

5. 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, 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.

6 / 10

6. What is the default Isolation Level?

Serializable

Read Committed

Repeatable Read

Read Uncommitted

7 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

8 / 10

8. Which of the below are valid Isolations Levels?

choose 2

Serializable

Rollback Read

Random Scatter

Read Committed

9 / 10

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

choose 3

Repeatable Read

Read Committed

Read Uncommitted

Serializable

10 / 10

10. Which parameters sets the database default isolation level?

default_transaction_isolation

transaction_isolation_level

default_isolation_level

active_transaction_isolation

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. When a transaction is committed Postgres uses a special <replace with answer> structure?

archive log

redo log

transaction log

commit log

2 / 10

2. CLOG Pages are never cached in memory?

False

True

3 / 10

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

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

Each pointer uses 8 bytes

Also know as the pages table of contents

stored in PGDATA/itemptr directory

Each pointer uses 4 bytes

6 / 10

6. CLOG files are stored in which directory?

PGDATA/pg_clog

PGDATA/pg_commit

PGDATA/pg_xact

PGDATA/clog

7 / 10

7. a transaction containing a savepoint is will still be considered as only a single transaction?

False

True

8 / 10

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

xmax

xid

xmin

xmas

9 / 10

9. Page free space can often become fragmented?

False

True

10 / 10

10. In Postgres, tables are often referred to as which of the below?

heap

view

dump

clog

Your score is

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