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 are used to define physical data layout?

False

True

2 / 20

2. 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

3 / 20

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

False

True

4 / 20

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

False

True

5 / 20

5. What is the purpose of the postgres database?

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

a template for all the other database

regular database that you can use at your discretion

No such database

6 / 20

6. If we create a new tablespace which directory will symbolic links be created from?

pg_tabspace

pg_symlinks

pg_tablespace

pg_tblspc

7 / 20

7. What is the purpose of the template1 database?

database used for temporary tables

regular database that you can use at your discretion

No such database

a template for all the other databases

8 / 20

8. Postgres uses a thread based process model?

False

True

9 / 20

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

write-ahead log (WAL)

online redo logs (ORL)

undo segments (UNDO)

rollback segments (RBS)

10 / 20

10. Each Database has its own System Catalog?

False

True

11 / 20

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

Initialize

StartNewPG

CreateCluster

CreatePGC

12 / 20

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

init

pginit

postman

postgres

13 / 20

13. Files are logically split into pages?

False

True

14 / 20

14. What is the point of the pg_global tablespace?

stores temporary tables that are common to the whole cluster

stores user tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

stores WAL logs used for global replication

15 / 20

15. TOAST tables reside in a seperate schema?

False

True

16 / 20

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

True

False

17 / 20

17. What is another name for the postgres process?

postmanager

postmaster

masterprocess

aurora

18 / 20

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

obj

oid#

oid

obj#

19 / 20

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

choose 3

tables

indexes

triggers

sequences

20 / 20

20. What is the purpose of wal writer?

flushes dirty pages to disk.

collects usage statistics for the instance.

executes checkpoints

writes WAL entries to disk

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. Which parameters sets the database default isolation level?

active_transaction_isolation

default_isolation_level

transaction_isolation_level

default_transaction_isolation

2 / 10

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

choose 3

Serializable

Read Uncommitted

Read Committed

Repeatable Read

3 / 10

3. What is the default Isolation Level?

Repeatable Read

Read Committed

Read Uncommitted

Serializable

4 / 10

4. 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

reading data direct from memory using pg_dirt

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

5 / 10

5. 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.

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

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.

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

6 / 10

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

True

False

7 / 10

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

False

True

8 / 10

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

Repeatable Read

Read Uncommitted

Read Committed

Serializable

9 / 10

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

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

10 / 10

10. 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, 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 once and modifies this row and commits the change.

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

xmas

xmax

xmin

xid

2 / 10

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

True

False

3 / 10

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

True

False

4 / 10

4. Page header sizes can be easily displayed using the <choose from answers> extension

pageheadinfo

pagesize

pagedetect

pageinspect

5 / 10

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

stored in PGDATA/itemptr directory

Also know as the pages table of contents

Each pointer uses 8 bytes

Each pointer uses 4 bytes

6 / 10

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

True

False

7 / 10

7. Information about subtransactions is stored under?

PGDATA/pg_xid

PGDATA/pg_subtrans

PGDATA/pg_min

PGDATA/subtrans

8 / 10

8. index row headers like table row headers contain xmin and xmax fields?

True

False

9 / 10

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

False

True

10 / 10

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

True

False

Your score is

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