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

True

False

2 / 20

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

rollback segments (RBS)

online redo logs (ORL)

write-ahead log (WAL)

undo segments (UNDO)

3 / 20

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

True

False

4 / 20

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

Choose 2 option

Postgres Server

Instance

Aurora

Quorum

5 / 20

5. How many rows in a page does Postgres aim to have before considering TOAST?

6 / 20

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

choose 3

indexes

tables

sequences

triggers

7 / 20

7. Which of below are predefined schemas?

choose 2

public

postgres

pg_catalog

system

8 / 20

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

BAKE

GROW

TOAST

BREAD

9 / 20

9. What is the purpose of autovacuum?

Removes stale data from tables and indexes

Deletes old logs and traces on disk

Rebuilds indexes with b level greater than 2

Performs a backup of WAL logs

10 / 20

10. What is the purpose of the template0 database?

Useful for creating development schemas

Useful for Postgres support Services to debug issues

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

No such database

11 / 20

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

PGTIPS

PGBASE

PGDATA

PGCORE

12 / 20

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

CreateCluster

CreatePGC

Initialize

StartNewPG

13 / 20

13. A single Postgres Instance can server only one database?

False

True

14 / 20

14. What is the purpose of the public schema?

restricted schema for postgres internal usage only

default schema for user objects

schema used for heterogeneous replication

no such schema

15 / 20

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

True

False

16 / 20

16. Which of below are predefined schemas?

choose 3

pg_toast

information_schema

pg_schema

pg_temp

17 / 20

17. 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

18 / 20

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

False

True

19 / 20

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

True

False

20 / 20

20. What is the point of the pg_global tablespace?

stores WAL logs used for global replication

stores user tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

stores temporary tables that are common to the whole cluster

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

False

True

2 / 10

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

Read Committed

Repeatable Read

Read Uncommitted

Serializable

3 / 10

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

False

True

4 / 10

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

False

True

5 / 10

5. 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 once and modifies this row 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.

6 / 10

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

reading data direct from memory using pg_dirt

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

reading the data directly from file using a text editor such as vi or notepad

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

7 / 10

7. Data Consistency is best handled at the application layer rather than at the database layer?

True

False

8 / 10

8. The SQL standard specifies three isolation levels?

True

False

9 / 10

9. Which of the below are valid Isolations Levels?

choose 2

Rollback Read

Read Committed

Random Scatter

Serializable

10 / 10

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

choose 3

Read Committed

Read Uncommitted

Serializable

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

False

True

2 / 10

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

redo log

transaction log

commit log

archive log

3 / 10

3. indexes do not use row versioning?

False

True

4 / 10

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

checksum

xmin

backend process ID

sequential number

5 / 10

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

COMMIT

INSERT

MERGE

DELETE

6 / 10

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

choose 2

flashback block

page header

free space

undo segment

7 / 10

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

True

False

8 / 10

8. virtual IDs exist only in PGDATA/pg_vxid when not cached?

True

False

9 / 10

9. Information about subtransactions is stored under?

PGDATA/pg_min

PGDATA/pg_subtrans

PGDATA/subtrans

PGDATA/pg_xid

10 / 10

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

False

True

Your score is

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