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

False

True

2 / 20

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

True

False

3 / 20

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

choose 3

tables

sequences

indexes

triggers

4 / 20

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

Initialize

StartNewPG

CreateCluster

CreatePGC

5 / 20

5. Tablespaces are used to define physical data layout?

True

False

6 / 20

6. What is the purpose of the postgres database?

No such 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

7 / 20

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

True

False

8 / 20

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

True

False

9 / 20

9. System Catalog tables begin with which prefix?

sys_

cat_

dba_

pg_

10 / 20

10. Which of below are predefined schemas?

choose 3

pg_toast

information_schema

pg_temp

pg_schema

11 / 20

11. Each Database has its own System Catalog?

True

False

12 / 20

12. Postgres by default has built in connection pooling abilities?

True

False

13 / 20

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

BAKE

TOAST

BREAD

GROW

14 / 20

14. What is the purpose of the template0 database?

Useful for creating development schemas

No such database

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

Useful for Postgres support Services to debug issues

15 / 20

15. What is the purpose of wal writer?

collects usage statistics for the instance.

flushes dirty pages to disk.

writes WAL entries to disk

executes checkpoints

16 / 20

16. Which of below are predefined schemas?

choose 2

public

pg_catalog

system

postgres

17 / 20

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

vacuum space map

used space map

free space map

wal space map

18 / 20

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

Main fork

table map

visiblilty map

free space map

19 / 20

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

online redo logs (ORL)

undo segments (UNDO)

rollback segments (RBS)

write-ahead log (WAL)

20 / 20

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

choose 2

pg_temp

pg_default

pg_global

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. Which parameters sets the database default isolation level?

active_transaction_isolation

default_transaction_isolation

default_isolation_level

transaction_isolation_level

2 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

3 / 10

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

True

False

4 / 10

4. The SQL standard specifies three isolation levels?

True

False

5 / 10

5. What is the default Isolation Level?

Serializable

Read Committed

Read Uncommitted

Repeatable Read

6 / 10

6. 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 twice, another transaction modifies this row between these reads issue a rollback.

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 once and modifies this row and commits the change.

7 / 10

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

Read Uncommitted

Serializable

Read Committed

Repeatable Read

8 / 10

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

False

True

9 / 10

9. A phantom read anomaly occurs when?

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 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.

10 / 10

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

True

False

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 2 items does a Virtual XID consist of?

xmin

checksum

backend process ID

sequential number

2 / 10

2. Tuples can also be referred to as columns?

True

False

3 / 10

3. Postgres table physical data files are always cross compatible across platforms?

True

False

4 / 10

4. CLOG files are stored in which directory?

PGDATA/pg_clog

PGDATA/pg_xact

PGDATA/clog

PGDATA/pg_commit

5 / 10

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

Each pointer uses 8 bytes

stored in PGDATA/itemptr directory

Each pointer uses 4 bytes

Also know as the pages table of contents

6 / 10

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

False

True

7 / 10

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

redo log

transaction log

archive log

commit log

8 / 10

8. Page free space can often become fragmented?

True

False

9 / 10

9. CLOG Pages are never cached in memory?

True

False

10 / 10

10. What does an Item Pointer contain?

choose 3

tuple xid

tuple status

tuple length

tuple offset from the start of the page

Your score is

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