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)

undo segments (UNDO)

rollback segments (RBS)

write-ahead log (WAL)

2 / 20

2. What is the purpose of the postgres database?

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

a template for all the other database

regular database that you can use at your discretion

No such database

3 / 20

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

pg_tabspace

pg_tblspc

pg_tablespace

pg_symlinks

4 / 20

4. What is a schema?

A memory area used to cache data from LRU chains

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

5 / 20

5. What is the name of the system catalog table for relations?

pg_system

pg_class

pg_catalog

pg_tables

6 / 20

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

False

True

7 / 20

7. What is the purpose of the public schema?

restricted schema for postgres internal usage only

default schema for user objects

no such schema

schema used for heterogeneous replication

8 / 20

8. Each Database has its own System Catalog?

True

False

9 / 20

9. What is the purpose of autovacuum?

Removes stale data from tables and indexes

Deletes old logs and traces on disk

Rebuilds indexes with b level greater than 2

Performs a backup of WAL logs

10 / 20

10. Which of below are predefined schemas?

choose 2

system

pg_catalog

postgres

public

11 / 20

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

False

True

12 / 20

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

Choose 2 option

Instance

Aurora

Quorum

Postgres Server

13 / 20

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

False

True

14 / 20

14. What is another name for the postgres process?

postmaster

masterprocess

aurora

postmanager

15 / 20

15. What is the purpose of the visibility map?

shows a page to be vacuumed or frozen

provides an audit trail for the database

shows referential relationships for tables

provides the data decryption key

16 / 20

16. Postgres uses a thread based process model?

True

False

17 / 20

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

18 / 20

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

True

False

19 / 20

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

free space map

Main fork

visiblilty map

table map

20 / 20

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

obj

oid#

obj#

oid

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

False

True

2 / 10

2. The SQL standard specifies three isolation levels?

True

False

3 / 10

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

False

True

4 / 10

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

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

reading data direct from memory using pg_dirt

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

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

5 / 10

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

False

True

6 / 10

6. What is the acronym used for the attributes that ensure Data consistency, integrity and durability?

HIPPA

ACID

SOC2

SAFE

7 / 10

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

True

False

8 / 10

8. 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 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 adds some other rows satisfying this condition and commits.

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?

Serializable

Read Uncommitted

Read Committed

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

True

False

2 / 10

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

True

False

3 / 10

3. The page Special Space is located at the start of the page with highest address

False

True

4 / 10

4. The page header stores checksum and the sizes of the other parts of the page?

False

True

5 / 10

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

False

True

6 / 10

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

pg_current_xact_id()

pg_current_xmin_id()

pg_current_commit_id()

pg_current_id()

7 / 10

7. Indexes values also support multi versioning with several versions of an index value existing at any point in time?

True

False

8 / 10

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

magic XID

virtual XID

temporary XID

heap XID

9 / 10

9. UPDATE can be regarded as which 2 separate operations?

INSERT

MERGE

COMMIT

DELETE

10 / 10

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

Each pointer uses 4 bytes

stored in PGDATA/itemptr directory

Also know as the pages table of contents

Each pointer uses 8 bytes

Your score is

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