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 uses a thread based process model?

False

True

2 / 20

2. Which of below are predefined schemas?

choose 3

information_schema

pg_temp

pg_toast

pg_schema

3 / 20

3. Which fork contains the actual table data?

free space map

visiblilty map

Main fork

table map

4 / 20

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

GROW

BREAD

TOAST

BAKE

5 / 20

5. Users should not modify the template0 database

True

False

6 / 20

6. What is the purpose of the public schema?

default schema for user objects

no such schema

restricted schema for postgres internal usage only

schema used for heterogeneous replication

7 / 20

7. What is the purpose of wal writer?

writes WAL entries to disk

collects usage statistics for the instance.

flushes dirty pages to disk.

executes checkpoints

8 / 20

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

9 / 20

9. What is another name for the postgres process?

postmaster

masterprocess

aurora

postmanager

10 / 20

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

False

True

11 / 20

11. What is the purpose of the postgres database?

regular database that you can use at your discretion

No such database

a template for all the other database

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

12 / 20

12. Files are logically split into pages?

True

False

13 / 20

13. The default Page size is 2k?

True

False

14 / 20

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

pg_class

pg_system

pg_tables

pg_catalog

15 / 20

15. System Catalog tables begin with which prefix?

sys_

dba_

cat_

pg_

16 / 20

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

1MB

1GB

5MB

5GB

17 / 20

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

True

False

18 / 20

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

19 / 20

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

True

False

20 / 20

20. Which fork is specific for unlogged tables?

free space map

Initialization fork

visiblilty map

Main fork

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. A phantom read anomaly occurs when?

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.

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

2 / 10

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

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

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

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

reading data direct from memory using pg_dirt

3 / 10

3. The SQL standard specifies three isolation levels?

True

False

4 / 10

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

True

False

5 / 10

5. 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 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.

6 / 10

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

False

True

7 / 10

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

True

False

8 / 10

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

SAFE

ACID

SOC2

HIPPA

9 / 10

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

False

True

10 / 10

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

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL 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. The page header is located in the highest address?

True

False

3 / 10

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

True

False

4 / 10

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

xmax

xid

xmin

xtime

5 / 10

5. CLOG files are stored in which directory?

PGDATA/pg_clog

PGDATA/pg_commit

PGDATA/pg_xact

PGDATA/clog

6 / 10

6. Tuples can also be referred to as columns?

False

True

7 / 10

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

False

True

8 / 10

8. indexes do not use row versioning?

True

False

9 / 10

9. 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

10 / 10

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

False

True

Your score is

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