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

True

False

2 / 20

2. Which 3 databases exist directly after cluster initialization?

choose 3 options

sysaux

template1

template0

postgres

3 / 20

3. TOAST tables reside in a seperate schema?

False

True

4 / 20

4. Which of below are predefined schemas?

choose 3

pg_toast

pg_temp

pg_schema

information_schema

5 / 20

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

TOAST

BREAD

GROW

BAKE

6 / 20

6. What is the purpose of the visibility map?

provides an audit trail for the database

shows a page to be vacuumed or frozen

shows referential relationships for tables

provides the data decryption key

7 / 20

7. Users should not modify the template0 database

True

False

8 / 20

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

Choose 2 option

Instance

Quorum

Aurora

Postgres Server

9 / 20

9. What is the purpose of wal writer?

writes WAL entries to disk

collects usage statistics for the instance.

flushes dirty pages to disk.

executes checkpoints

10 / 20

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

True

False

11 / 20

11. What is the purpose of the template0 database?

No such database

Useful for creating development schemas

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

Useful for Postgres support Services to debug issues

12 / 20

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

PGDATA

PGTIPS

PGCORE

PGBASE

13 / 20

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

oid#

obj

oid

obj#

14 / 20

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

False

True

15 / 20

15. What is the point of the pg_global tablespace?

stores system catalog objects that are common to the whole cluster

stores WAL logs used for global replication

stores temporary tables that are common to the whole cluster

stores user tables that are common to the whole cluster

16 / 20

16. Tablespaces are used to define physical data layout?

False

True

17 / 20

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

True

False

18 / 20

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

True

False

19 / 20

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

Directory Path

Access Path

Search Path

Schema Path

20 / 20

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

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?

True

False

2 / 10

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

False

True

3 / 10

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

True

False

4 / 10

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

choose 3

Read Committed

Read Uncommitted

Repeatable Read

Serializable

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

Issues a rollback after the commit to satisfy repeatable read.

Replace procedural code with declarative one.

Apply explicit locks

6 / 10

6. Which of the below are valid Isolations Levels?

choose 2

Serializable

Random Scatter

Read Committed

Rollback Read

7 / 10

7. A phantom read anomaly occurs when?

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 also queries this same data.

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 adds some other rows satisfying this condition and commits.

8 / 10

8. The SQL standard specifies three isolation levels?

False

True

9 / 10

9. Which parameters sets the database default isolation level?

default_isolation_level

default_transaction_isolation

active_transaction_isolation

transaction_isolation_level

10 / 10

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

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

CREATE EXTENSTION 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. 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. CLOG Pages are never cached in memory?

False

True

3 / 10

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

True

False

4 / 10

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

False

True

5 / 10

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

archive log

transaction log

commit log

redo log

6 / 10

6. Which 2 items does a Virtual XID consist of?

sequential number

backend process ID

xmin

checksum

7 / 10

7. When a row is created, its xmin value is set to the transaction ID of which command?

DELETE

COMMIT

CREATE

INSERT

8 / 10

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

True

False

9 / 10

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

pageheadinfo

pagedetect

pageinspect

pagesize

10 / 10

10. Which 2 of the below represent transaction IDs used for row versioning?

xid

xmin

xmax

xtime

Your score is

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