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. What column in system catalogs servers as the Primary Key

oid#

obj#

obj

oid

2 / 20

2. The default Page size is 2k?

True

False

3 / 20

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

False

True

4 / 20

4. What is a schema?

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

The name used to refer to a super user account

5 / 20

5. How does Postgres know which schema to use if not specified?

Access Path

Schema Path

Directory Path

Search Path

6 / 20

6. System Catalog tables begin with which prefix?

dba_

sys_

cat_

pg_

7 / 20

7. Each Database has its own System Catalog?

False

True

8 / 20

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

False

True

9 / 20

9. What is the purpose of autovacuum?

Deletes old logs and traces on disk

Performs a backup of WAL logs

Rebuilds indexes with b level greater than 2

Removes stale data from tables and indexes

10 / 20

10. Which fork contains the actual table data?

table map

free space map

visiblilty map

Main fork

11 / 20

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

True

False

12 / 20

12. What is the purpose of the template1 database?

regular database that you can use at your discretion

a template for all the other databases

database used for temporary tables

No such database

13 / 20

13. To be able to restore data consistency, Postgres maintains

write-ahead log (WAL)

online redo logs (ORL)

rollback segments (RBS)

undo segments (UNDO)

14 / 20

14. What is another name for the postgres process?

aurora

postmanager

masterprocess

postmaster

15 / 20

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

pg_catalog

pg_tables

pg_system

pg_class

16 / 20

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

5MB

5GB

1GB

1MB

17 / 20

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

choose 3

sequences

tables

indexes

triggers

18 / 20

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

False

True

19 / 20

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

Choose 2 option

Instance

Postgres Server

Quorum

Aurora

20 / 20

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

True

False

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

Repeatable Read

Read Uncommitted

Read Committed

Serializable

3 / 10

3. The SQL standard specifies three isolation levels?

True

False

4 / 10

4. Which of the below are valid Isolations Levels?

choose 2

Serializable

Read Committed

Random Scatter

Rollback Read

5 / 10

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

Select more than 1 answer below:

Use a single SQL operator

Apply explicit locks

Issues a rollback after the commit to satisfy repeatable read.

Replace procedural code with declarative one.

6 / 10

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

False

True

7 / 10

7. 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

8 / 10

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

ACID

SAFE

HIPPA

SOC2

9 / 10

9. 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 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.

10 / 10

10. Which parameters sets the database default isolation level?

default_isolation_level

transaction_isolation_level

default_transaction_isolation

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

False

True

2 / 10

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

True

False

3 / 10

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

Each pointer uses 8 bytes

stored in PGDATA/itemptr directory

Also know as the pages table of contents

Each pointer uses 4 bytes

4 / 10

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

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_xmin_id()

pg_current_id()

pg_current_xact_id()

pg_current_commit_id()

7 / 10

7. status of a subtransaction is written into CLOG?

False

True

8 / 10

8. Each page has a layer that usually consists of?

choose 2

flashback block

undo segment

page header

free space

9 / 10

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

False

True

10 / 10

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

False

True

Your score is

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