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. Files are logically split into pages?

False

True

2 / 20

2. Which of below are predefined schemas?

choose 3

information_schema

pg_schema

pg_toast

pg_temp

3 / 20

3. Users should not modify the template0 database

False

True

4 / 20

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

choose 3

triggers

sequences

indexes

tables

5 / 20

5. Which of below are predefined schemas?

choose 2

pg_catalog

postgres

public

system

6 / 20

6. What is a schema?

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

A memory area used to cache data from LRU chains

7 / 20

7. Each Database has its own System Catalog?

True

False

8 / 20

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

True

False

9 / 20

9. Tablespaces are used to define physical data layout?

True

False

10 / 20

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

11 / 20

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

pg_tabspace

pg_tblspc

pg_symlinks

pg_tablespace

12 / 20

12. What is the purpose of the template0 database?

Useful for creating development schemas

Useful for Postgres support Services to debug issues

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

No such database

13 / 20

13. Postgres uses a thread based process model?

False

True

14 / 20

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

choose 2

pg_tablespace

pg_default

pg_temp

pg_global

15 / 20

15. System Catalog tables begin with which prefix?

sys_

dba_

cat_

pg_

16 / 20

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

False

True

17 / 20

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

Egor Rogov

Dan Brown

Paul Sammy

Sam Altman

18 / 20

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

False

True

19 / 20

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

True

False

20 / 20

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

used space map

vacuum space map

free space map

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

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

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

reading data direct from memory using pg_dirt

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

2 / 10

2. non-repeatable read anomaly occurs when?

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 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.

3 / 10

3. A phantom read anomaly occurs when?

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.

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

4 / 10

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

False

True

5 / 10

5. The SQL standard specifies three isolation levels?

True

False

6 / 10

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

choose 3

Read Committed

Read Uncommitted

Serializable

Repeatable Read

7 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

8 / 10

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

Select more than 1 answer below:

Apply explicit locks

Use a single SQL operator

Replace procedural code with declarative one.

Issues a rollback after the commit to satisfy repeatable read.

9 / 10

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

True

False

10 / 10

10. What is the default Isolation Level?

Read Uncommitted

Repeatable Read

Read Committed

Serializable

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. CLOG contains how many bits for each transaction?

2 / 10

2. Information about subtransactions is stored under?

PGDATA/subtrans

PGDATA/pg_min

PGDATA/pg_xid

PGDATA/pg_subtrans

3 / 10

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

False

True

4 / 10

4. indexes do not use row versioning?

False

True

5 / 10

5. CLOG files are stored in which directory?

PGDATA/clog

PGDATA/pg_xact

PGDATA/pg_clog

PGDATA/pg_commit

6 / 10

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

True

False

7 / 10

7. The page header is located in the highest address?

True

False

8 / 10

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

True

False

9 / 10

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

virtual XID

temporary XID

heap XID

magic XID

10 / 10

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

True

False

Your score is

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