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

False

True

2 / 20

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

choose 2

pg_global

pg_default

pg_tablespace

pg_temp

3 / 20

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

False

True

4 / 20

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

True

False

5 / 20

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

6 / 20

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

5MB

1MB

5GB

1GB

7 / 20

7. System Catalog tables begin with which prefix?

cat_

sys_

pg_

dba_

8 / 20

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

CreateCluster

Initialize

StartNewPG

CreatePGC

9 / 20

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

10 / 20

10. What is the purpose of the template1 database?

database used for temporary tables

a template for all the other databases

No such database

regular database that you can use at your discretion

11 / 20

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

BAKE

GROW

TOAST

BREAD

12 / 20

12. TOAST tables reside in a seperate schema?

False

True

13 / 20

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

used space map

vacuum space map

wal space map

free space map

14 / 20

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

True

False

15 / 20

15. The default Page size is 2k?

False

True

16 / 20

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

True

False

17 / 20

17. Files are logically split into pages?

True

False

18 / 20

18. What is the purpose of the public schema?

restricted schema for postgres internal usage only

schema used for heterogeneous replication

default schema for user objects

no such schema

19 / 20

19. What is the purpose of the template0 database?

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

Useful for creating development schemas

20 / 20

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

Search Path

Access Path

Directory Path

Schema Path

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, 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 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.

2 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

3 / 10

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

choose 3

Read Committed

Serializable

Read Uncommitted

Repeatable Read

4 / 10

4. What is the default Isolation Level?

Repeatable Read

Serializable

Read Uncommitted

Read Committed

5 / 10

5. Which of the below are valid Isolations Levels?

choose 2

Rollback Read

Serializable

Read Committed

Random Scatter

6 / 10

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

False

True

7 / 10

7. 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 adds some other rows satisfying this condition and commits.

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 also queries this same data.

The same transactions issues a commit, then a rollback to restore data to its original value

8 / 10

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

True

False

9 / 10

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

False

True

10 / 10

10. 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.

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

Apply explicit locks

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. The page Special Space is located at the start of the page with highest address

False

True

2 / 10

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

False

True

3 / 10

3. status of a subtransaction is written into CLOG?

True

False

4 / 10

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

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. CLOG contains how many bits for each transaction?

7 / 10

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

choose 2

free space

flashback block

page header

undo segment

8 / 10

8. Page free space can often become fragmented?

True

False

9 / 10

9. at any one time Postgres can have several versions of a row?

False

True

10 / 10

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

DELETE

INSERT

COMMIT

CREATE

Your score is

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