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. Which of below are predefined schemas?

choose 2

pg_catalog

postgres

system

public

2 / 20

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

choose 2

pg_global

pg_default

pg_tablespace

pg_temp

3 / 20

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

False

True

4 / 20

4. The default Page size is 2k?

True

False

5 / 20

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

True

False

6 / 20

6. Users should not modify the template0 database

False

True

7 / 20

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

True

False

8 / 20

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

False

True

9 / 20

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

10 / 20

10. Each tablespaces can only be assigned for use by one database

False

True

11 / 20

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

True

False

12 / 20

12. What is the purpose of the template0 database?

Useful for Postgres support Services to debug issues

Useful for restoring data from a logical backup or creating a database with a different encoding

Useful for creating development schemas

No such database

13 / 20

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

False

True

14 / 20

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

pg_symlinks

pg_tablespace

pg_tblspc

pg_tabspace

15 / 20

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

used space map

wal space map

free space map

vacuum space map

16 / 20

16. What is the purpose of the postgres database?

restoring data from a logical backup or creating a database with a different encoding

regular database that you can use at your discretion

a template for all the other database

No such database

17 / 20

17. TOAST tables reside in a seperate schema?

True

False

18 / 20

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

PGCORE

PGDATA

PGBASE

PGTIPS

19 / 20

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

False

True

20 / 20

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

Main fork

table map

free space map

visiblilty map

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. 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, 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.

2 / 10

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

True

False

3 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

4 / 10

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

False

True

5 / 10

5. What is the default Isolation Level?

Read Committed

Serializable

Repeatable Read

Read Uncommitted

6 / 10

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

Read Uncommitted

Read Committed

Repeatable Read

Serializable

7 / 10

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

True

False

8 / 10

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

False

True

9 / 10

9. 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.

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

Apply explicit locks

10 / 10

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

choose 3

Serializable

Repeatable Read

Read Uncommitted

Read Committed

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

Each pointer uses 4 bytes

Each pointer uses 8 bytes

stored in PGDATA/itemptr directory

Also know as the pages table of contents

2 / 10

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

True

False

3 / 10

3. psql provides a special mode that allows you to continue a transaction after a failure?

False

True

4 / 10

4. CLOG contains how many bits for each transaction?

5 / 10

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

virtual XID

magic XID

temporary XID

heap XID

6 / 10

6. indexes do not use row versioning?

True

False

7 / 10

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

False

True

8 / 10

8. Page free space can often become fragmented?

True

False

9 / 10

9. Information about subtransactions is stored under?

PGDATA/pg_xid

PGDATA/subtrans

PGDATA/pg_subtrans

PGDATA/pg_min

10 / 10

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

pg_current_xmin_id()

pg_current_commit_id()

pg_current_xact_id()

pg_current_id()

Your score is

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