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

online redo logs (ORL)

rollback segments (RBS)

write-ahead log (WAL)

undo segments (UNDO)

2 / 20

2. Which of the below objects can be referred to as relations?

choose 3

tables

triggers

indexes

sequences

3 / 20

3. Each Database has its own System Catalog?

True

False

4 / 20

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

PGBASE

PGTIPS

PGDATA

PGCORE

5 / 20

5. Who is the Author of the Postgres 14 Internals book?

Egor Rogov

Sam Altman

Dan Brown

Paul Sammy

6 / 20

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

1MB

5MB

5GB

1GB

7 / 20

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

True

False

8 / 20

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

9 / 20

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

True

False

10 / 20

10. Which fork contains the actual table data?

visiblilty map

table map

free space map

Main fork

11 / 20

11. Which fork keeps track of available space within pages?

used space map

vacuum space map

free space map

wal space map

12 / 20

12. What is a schema?

The name used to refer to a super user account

Namespace that store all objects of a database

This is the same as a user in Postgres

A memory area used to cache data from LRU chains

13 / 20

13. The default Page size is 2k?

True

False

14 / 20

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

init

postman

pginit

postgres

15 / 20

15. What is the purpose of the public schema?

restricted schema for postgres internal usage only

no such schema

default schema for user objects

schema used for heterogeneous replication

16 / 20

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

False

True

17 / 20

17. 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

a template for all the other database

regular database that you can use at your discretion

18 / 20

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

True

False

19 / 20

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

visiblilty map

table map

Main fork

free space map

20 / 20

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

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

True

False

2 / 10

2. 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 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 and commits the change.

3 / 10

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

choose 3

Serializable

Repeatable Read

Read Uncommitted

Read Committed

4 / 10

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

True

False

5 / 10

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

Repeatable Read

Read Committed

Serializable

Read Uncommitted

6 / 10

6. Which parameters sets the database default isolation level?

active_transaction_isolation

transaction_isolation_level

default_isolation_level

default_transaction_isolation

7 / 10

7. The SQL standard specifies three isolation levels?

True

False

8 / 10

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

True

False

9 / 10

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

False

True

10 / 10

10. 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;

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. A page along with its tuples is read into the buffer cache with compression transformations to enhance cache efficiency?

False

True

2 / 10

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

INSERT

DELETE

CREATE

COMMIT

3 / 10

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

pageheadinfo

pagesize

pageinspect

pagedetect

4 / 10

4. CLOG files are stored in which directory?

PGDATA/pg_commit

PGDATA/pg_xact

PGDATA/clog

PGDATA/pg_clog

5 / 10

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

False

True

6 / 10

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

True

False

7 / 10

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

True

False

8 / 10

8. Page free space can often become fragmented?

False

True

9 / 10

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

backend process ID

xmin

sequential number

checksum

10 / 10

10. indexes do not use row versioning?

False

True

Your score is

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