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

3 / 20

3. Postgres server spawns a new backend session for each connection?

False

True

4 / 20

4. What is the purpose of wal writer?

writes WAL entries to disk

flushes dirty pages to disk.

executes checkpoints

collects usage statistics for the instance.

5 / 20

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

True

False

6 / 20

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

True

False

7 / 20

7. Which of below are predefined schemas?

choose 2

postgres

public

system

pg_catalog

8 / 20

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

write-ahead log (WAL)

rollback segments (RBS)

online redo logs (ORL)

undo segments (UNDO)

9 / 20

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

Initialize

StartNewPG

CreateCluster

CreatePGC

10 / 20

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

pg_symlinks

pg_tblspc

pg_tabspace

pg_tablespace

11 / 20

11. Which 3 databases exist directly after cluster initialization?

choose 3 options

sysaux

postgres

template1

template0

12 / 20

12. Files are logically split into pages?

True

False

13 / 20

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

False

True

14 / 20

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

wal space map

vacuum space map

used space map

free space map

15 / 20

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

choose 3

sequences

triggers

tables

indexes

16 / 20

16. Users should not modify the template0 database

True

False

17 / 20

17. What is the point of the pg_global tablespace?

stores temporary tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

stores user tables that are common to the whole cluster

stores WAL logs used for global replication

18 / 20

18. What is the purpose of the postgres database?

No such 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

19 / 20

19. What is the name of the catalog that stores metadata for all cluster objects?

Sysaux Catalog

Sys Catalog

Sysasm Catalog

System Catalog

20 / 20

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

choose 2

pg_tablespace

pg_global

pg_default

pg_temp

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

SAFE

ACID

HIPPA

SOC2

2 / 10

2. Which parameters sets the database default isolation level?

transaction_isolation_level

active_transaction_isolation

default_transaction_isolation

default_isolation_level

3 / 10

3. Which of the below are valid Isolations Levels?

choose 2

Random Scatter

Rollback Read

Serializable

Read Committed

4 / 10

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

True

False

5 / 10

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

True

False

6 / 10

6. 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 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 once, another transaction modifies this row between these reads and commits the change.

7 / 10

7. The SQL standard specifies three isolation levels?

False

True

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.

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

9 / 10

9. What is the default Isolation Level?

Repeatable Read

Read Uncommitted

Serializable

Read Committed

10 / 10

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

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. Each page has a layer that usually consists of?

choose 2

undo segment

page header

free space

flashback block

2 / 10

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

False

True

3 / 10

3. Information about subtransactions is stored under?

PGDATA/subtrans

PGDATA/pg_xid

PGDATA/pg_subtrans

PGDATA/pg_min

4 / 10

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

True

False

5 / 10

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

xmas

xid

xmax

xmin

6 / 10

6. Tuples can also be referred to as columns?

True

False

7 / 10

7. What does an Item Pointer contain?

choose 3

tuple xid

tuple length

tuple status

tuple offset from the start of the page

8 / 10

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

True

False

9 / 10

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

True

False

10 / 10

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

False

True

Your score is

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