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 column in system catalogs servers as the Primary Key

obj#

obj

oid#

oid

2 / 20

2. What is the purpose of the postgres database?

a template for all the other database

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

regular database that you can use at your discretion

No such database

3 / 20

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

1GB

5MB

1MB

5GB

4 / 20

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

5 / 20

5. A schema can belong to more than one database?

True

False

6 / 20

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

Initialize

CreateCluster

CreatePGC

StartNewPG

7 / 20

7. Which fork is specific for unlogged tables?

free space map

Main fork

visiblilty map

Initialization fork

8 / 20

8. System Catalog tables begin with which prefix?

pg_

dba_

cat_

sys_

9 / 20

9. Which fork contains the actual table data?

table map

Main fork

free space map

visiblilty map

10 / 20

10. What is another name for the postgres process?

postmanager

masterprocess

aurora

postmaster

11 / 20

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

PGBASE

PGTIPS

PGCORE

PGDATA

12 / 20

12. Files are logically split into pages?

True

False

13 / 20

13. What is the point of the pg_global tablespace?

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

stores temporary tables that are common to the whole cluster

14 / 20

14. Who is the Author of the Postgres 14 Internals book?

Egor Rogov

Dan Brown

Sam Altman

Paul Sammy

15 / 20

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

True

False

16 / 20

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

rollback segments (RBS)

undo segments (UNDO)

online redo logs (ORL)

write-ahead log (WAL)

17 / 20

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

True

False

18 / 20

18. TOAST tables reside in a seperate schema?

False

True

19 / 20

19. The default Page size is 2k?

False

True

20 / 20

20. What is the purpose of the public schema?

schema used for heterogeneous replication

no such schema

default schema for user objects

restricted schema for postgres internal usage only

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 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.

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.

2 / 10

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

False

True

3 / 10

3. Which parameters sets the database default isolation level?

default_isolation_level

transaction_isolation_level

default_transaction_isolation

active_transaction_isolation

4 / 10

4. Which of the below are valid Isolations Levels?

choose 2

Rollback Read

Read Committed

Serializable

Random Scatter

5 / 10

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

Serializable

Repeatable Read

Read Uncommitted

Read Committed

6 / 10

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

choose 3

Read Uncommitted

Repeatable Read

Serializable

Read Committed

7 / 10

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

False

True

8 / 10

8. A phantom read anomaly occurs when?

A transactions inserts a null value into a not null columns 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 adds some other rows satisfying this condition 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.

9 / 10

9. What is the default Isolation Level?

Repeatable Read

Read Uncommitted

Serializable

Read Committed

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. What does an Item Pointer contain?

choose 3

tuple status

tuple length

tuple offset from the start of the page

tuple xid

2 / 10

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

True

False

3 / 10

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

False

True

4 / 10

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

stored in PGDATA/itemptr directory

Each pointer uses 8 bytes

Each pointer uses 4 bytes

Also know as the pages table of contents

5 / 10

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

True

False

6 / 10

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

True

False

7 / 10

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

False

True

8 / 10

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

COMMIT

DELETE

INSERT

CREATE

9 / 10

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

True

False

10 / 10

10. CLOG contains how many bits for each transaction?

Your score is

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