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. Postgres by default has built in connection pooling abilities?

False

True

2 / 20

2. The default Page size is 2k?

True

False

3 / 20

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

True

False

4 / 20

4. What is the purpose of the visibility map?

provides the data decryption key

provides an audit trail for the database

shows a page to be vacuumed or frozen

shows referential relationships for tables

5 / 20

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

False

True

6 / 20

6. Which fork contains the actual table data?

visiblilty map

free space map

table map

Main fork

7 / 20

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

8 / 20

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

False

True

9 / 20

9. What is another name for the postgres process?

postmaster

aurora

masterprocess

postmanager

10 / 20

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

postgres

init

postman

pginit

11 / 20

11. What is the purpose of the template1 database?

database used for temporary tables

No such database

a template for all the other databases

regular database that you can use at your discretion

12 / 20

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

False

True

13 / 20

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

False

True

14 / 20

14. TOAST tables reside in a seperate schema?

False

True

15 / 20

15. Users should not modify the template0 database

False

True

16 / 20

16. What is the purpose of wal writer?

collects usage statistics for the instance.

executes checkpoints

writes WAL entries to disk

flushes dirty pages to disk.

17 / 20

17. What is the purpose of the public schema?

schema used for heterogeneous replication

default schema for user objects

restricted schema for postgres internal usage only

no such schema

18 / 20

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

Choose 2 option

Instance

Postgres Server

Aurora

Quorum

19 / 20

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

free space map

used space map

wal space map

vacuum space map

20 / 20

20. Postgres uses a thread based process model?

False

True

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

False

True

2 / 10

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

Select more than 1 answer below:

Use a single SQL operator

Apply explicit locks

Replace procedural code with declarative one.

Issues a rollback after the commit to satisfy repeatable read.

3 / 10

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

True

False

4 / 10

4. The SQL standard specifies three isolation levels?

True

False

5 / 10

5. 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 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 twice, another transaction modifies this row between these reads and commits the change.

6 / 10

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

True

False

7 / 10

7. Which of the below are valid Isolations Levels?

choose 2

Serializable

Read Committed

Rollback Read

Random Scatter

8 / 10

8. 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.

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.

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

A transactions inserts a null value into a not null columns and commits

9 / 10

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

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

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

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

reading data direct from memory using pg_dirt

10 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=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. virtual IDs exist only in PGDATA/pg_vxid when not cached?

True

False

2 / 10

2. Information about subtransactions is stored under?

PGDATA/pg_min

PGDATA/subtrans

PGDATA/pg_subtrans

PGDATA/pg_xid

3 / 10

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

Each pointer uses 8 bytes

Also know as the pages table of contents

stored in PGDATA/itemptr directory

Each pointer uses 4 bytes

4 / 10

4. Rows of TOAST tables are handled in such a way that they are never update?

False

True

5 / 10

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

xmax

xid

xtime

xmin

6 / 10

6. The page header stores checksum and the sizes of the other parts of the page?

False

True

7 / 10

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

True

False

8 / 10

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

xid

xmin

xmax

xmas

9 / 10

9. Which function can we use to find the current transaction ID?

pg_current_id()

pg_current_xact_id()

pg_current_xmin_id()

pg_current_commit_id()

10 / 10

10. a transaction containing a savepoint is will still be considered as only a single transaction?

False

True

Your score is

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