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 command is used to create the Postgres cluster?

CreateCluster

CreatePGC

StartNewPG

Initialize

2 / 20

2. Tablespaces can be used to segregate data based on performance needs?

False

True

3 / 20

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

postgres

postman

pginit

init

4 / 20

4. What is the purpose of wal writer?

executes checkpoints

collects usage statistics for the instance.

writes WAL entries to disk

flushes dirty pages to disk.

5 / 20

5. Postgres uses a thread based process model?

True

False

6 / 20

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

used space map

vacuum space map

free space map

wal space map

7 / 20

7. What is a schema?

The name used to refer to a super user account

Namespace that store all objects of a database

A memory area used to cache data from LRU chains

This is the same as a user in Postgres

8 / 20

8. A Postgres cluster consists of 2 or more physical servers accessing one Postgres Instance?

True

False

9 / 20

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

choose 2

pg_global

pg_temp

pg_tablespace

pg_default

10 / 20

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

Schema Path

Directory Path

Search Path

Access Path

11 / 20

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

False

True

12 / 20

12. What is the purpose of autovacuum?

Rebuilds indexes with b level greater than 2

Performs a backup of WAL logs

Deletes old logs and traces on disk

Removes stale data from tables and indexes

13 / 20

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

True

False

14 / 20

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

1GB

5GB

5MB

1MB

15 / 20

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

False

True

16 / 20

16. What is the purpose of the public schema?

schema used for heterogeneous replication

no such schema

restricted schema for postgres internal usage only

default schema for user objects

17 / 20

17. What is the purpose of the visibility map?

provides an audit trail for the database

shows referential relationships for tables

provides the data decryption key

shows a page to be vacuumed or frozen

18 / 20

18. Tablespaces are used to define physical data layout?

False

True

19 / 20

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

oid#

obj

obj#

oid

20 / 20

20. Which fork contains the actual table data?

Main fork

visiblilty map

free space map

table map

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

Select more than 1 answer below:

Replace procedural code with declarative one.

Apply explicit locks

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

2 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

3 / 10

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

False

True

4 / 10

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

Read Uncommitted

Serializable

Read Committed

Repeatable Read

5 / 10

5. 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 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 and commits the change.

6 / 10

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

ACID

HIPPA

SAFE

SOC2

7 / 10

7. The SQL standard specifies three isolation levels?

False

True

8 / 10

8. Which parameters sets the database default isolation level?

default_transaction_isolation

transaction_isolation_level

active_transaction_isolation

default_isolation_level

9 / 10

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

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

a session being able to see commited 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

10 / 10

10. What is the default Isolation Level?

Repeatable Read

Read Committed

Read Uncommitted

Serializable

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

True

False

2 / 10

2. Tuples can also be referred to as columns?

True

False

3 / 10

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

xtime

xid

xmin

xmax

4 / 10

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

Also know as the pages table of contents

Each pointer uses 8 bytes

stored in PGDATA/itemptr directory

Each pointer uses 4 bytes

5 / 10

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

archive log

redo log

commit log

transaction log

6 / 10

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

magic XID

heap XID

temporary XID

virtual XID

7 / 10

7. A page along with its tuples is read into the buffer cache with compression transformations to enhance cache efficiency?

True

False

8 / 10

8. CLOG Pages are never cached in memory?

False

True

9 / 10

9. Information about subtransactions is stored under?

PGDATA/pg_xid

PGDATA/pg_subtrans

PGDATA/subtrans

PGDATA/pg_min

10 / 10

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

DELETE

INSERT

COMMIT

MERGE

Your score is

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