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 template0 database?

No such database

Useful for Postgres support Services to debug issues

Useful for creating development schemas

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

2 / 20

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

TOAST

GROW

BAKE

BREAD

3 / 20

3. What is the purpose of the public schema?

schema used for heterogeneous replication

restricted schema for postgres internal usage only

no such schema

default schema for user objects

4 / 20

4. What is the name of the system catalog table for relations?

pg_class

pg_tables

pg_system

pg_catalog

5 / 20

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

6 / 20

6. Postgres uses a thread based process model?

True

False

7 / 20

7. Files are logically split into pages?

False

True

8 / 20

8. What is the point of the pg_global tablespace?

stores WAL logs used for global replication

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

9 / 20

9. What is the purpose of the template1 database?

regular database that you can use at your discretion

database used for temporary tables

No such database

a template for all the other databases

10 / 20

10. What is the purpose of the visibility map?

provides the data decryption key

shows referential relationships for tables

provides an audit trail for the database

shows a page to be vacuumed or frozen

11 / 20

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

Choose 2 option

Postgres Server

Quorum

Aurora

Instance

12 / 20

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

table map

Main fork

free space map

visiblilty map

13 / 20

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

choose 3

sequences

indexes

triggers

tables

14 / 20

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

True

False

15 / 20

15. What is the purpose of autovacuum?

Deletes old logs and traces on disk

Removes stale data from tables and indexes

Rebuilds indexes with b level greater than 2

Performs a backup of WAL logs

16 / 20

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

True

False

17 / 20

17. Each Database has its own System Catalog?

True

False

18 / 20

18. Which 3 databases exist directly after cluster initialization?

choose 3 options

postgres

sysaux

template1

template0

19 / 20

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

True

False

20 / 20

20. The default Page size is 2k?

True

False

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. 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 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.

A transaction reads one and the same row twice, another transaction modifies this row between these reads issue a rollback.

2 / 10

2. The SQL standard specifies three isolation levels?

False

True

3 / 10

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

True

False

4 / 10

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

Select more than 1 answer below:

Apply explicit locks

Replace procedural code with declarative one.

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

5 / 10

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

Read Committed

Serializable

Read Uncommitted

Repeatable Read

6 / 10

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

True

False

7 / 10

7. What is the default Isolation Level?

Repeatable Read

Read Uncommitted

Serializable

Read Committed

8 / 10

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

True

False

9 / 10

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

SOC2

SAFE

HIPPA

ACID

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

False

True

2 / 10

2. To identify different versions of one and the same row, PostgreSQL marks each of them with which two value?

xmas

xmax

xmin

xid

3 / 10

3. Information about subtransactions is stored under?

PGDATA/pg_xid

PGDATA/pg_min

PGDATA/subtrans

PGDATA/pg_subtrans

4 / 10

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

True

False

5 / 10

5. Page free space can often become fragmented?

True

False

6 / 10

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

INSERT

CREATE

COMMIT

DELETE

7 / 10

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

True

False

8 / 10

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

False

True

9 / 10

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

False

True

10 / 10

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

heap XID

temporary XID

magic XID

virtual XID

Your score is

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