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 is the purpose of the public schema?

default schema for user objects

restricted schema for postgres internal usage only

schema used for heterogeneous replication

no such schema

2 / 20

2. Tablespaces are used to define physical data layout?

True

False

3 / 20

3. TOAST tables reside in a seperate schema?

True

False

4 / 20

4. What is the point of the pg_global tablespace?

stores system catalog objects that are common to the whole cluster

stores temporary tables that are common to the whole cluster

stores user tables that are common to the whole cluster

stores WAL logs used for global replication

5 / 20

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

True

False

6 / 20

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

True

False

7 / 20

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

True

False

8 / 20

8. Each Database has its own System Catalog?

False

True

9 / 20

9. What is the purpose of wal writer?

flushes dirty pages to disk.

executes checkpoints

writes WAL entries to disk

collects usage statistics for the instance.

10 / 20

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

Dan Brown

Egor Rogov

Paul Sammy

Sam Altman

11 / 20

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

choose 3

indexes

tables

sequences

triggers

12 / 20

12. What is the name of the mechanism used to store a row bigger than a page size?

TOAST

BREAD

GROW

BAKE

13 / 20

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

init

pginit

postman

postgres

14 / 20

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

Schema Path

Directory Path

Access Path

Search Path

15 / 20

15. What command is used to create the Postgres cluster?

CreateCluster

StartNewPG

Initialize

CreatePGC

16 / 20

16. What is the purpose of the template0 database?

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

Useful for creating development schemas

No such database

Useful for Postgres support Services to debug issues

17 / 20

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

obj

oid#

oid

obj#

18 / 20

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

False

True

19 / 20

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

True

False

20 / 20

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

choose 2

pg_global

pg_temp

pg_default

pg_tablespace

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. 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.

2 / 10

2. 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 commited data altered by another session

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

reading data direct from memory using pg_dirt

3 / 10

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

False

True

4 / 10

4. Which parameters sets the database default isolation level?

active_transaction_isolation

default_transaction_isolation

transaction_isolation_level

default_isolation_level

5 / 10

5. The SQL standard specifies three isolation levels?

False

True

6 / 10

6. What is the default Isolation Level?

Read Uncommitted

Repeatable Read

Serializable

Read Committed

7 / 10

7. 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

Replace procedural code with declarative one.

Issues a rollback after the commit to satisfy repeatable read.

8 / 10

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

Read Committed

Serializable

Repeatable Read

Read Uncommitted

9 / 10

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

False

True

10 / 10

10. 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.

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 Pages are never cached in memory?

True

False

2 / 10

2. When a transaction is committed Postgres uses a special <replace with answer> structure?

transaction log

archive log

commit log

redo log

3 / 10

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

MERGE

DELETE

COMMIT

INSERT

4 / 10

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

pageinspect

pagedetect

pageheadinfo

pagesize

5 / 10

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

temporary XID

heap XID

magic XID

virtual XID

6 / 10

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

False

True

7 / 10

7. Information about subtransactions is stored under?

PGDATA/subtrans

PGDATA/pg_subtrans

PGDATA/pg_xid

PGDATA/pg_min

8 / 10

8. Tuples can also be referred to as columns?

True

False

9 / 10

9. status of a subtransaction is written into CLOG?

True

False

10 / 10

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

True

False

Your score is

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