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. The default Page size is 2k?

False

True

2 / 20

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

True

False

3 / 20

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

GROW

BAKE

TOAST

BREAD

4 / 20

4. System Catalog tables begin with which prefix?

pg_

dba_

cat_

sys_

5 / 20

5. What is the purpose of wal writer?

collects usage statistics for the instance.

executes checkpoints

flushes dirty pages to disk.

writes WAL entries to disk

6 / 20

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

choose 2

pg_default

pg_tablespace

pg_temp

pg_global

7 / 20

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

False

True

8 / 20

8. What is the purpose of the template1 database?

a template for all the other databases

No such database

regular database that you can use at your discretion

database used for temporary tables

9 / 20

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

System Catalog

Sys Catalog

Sysasm Catalog

Sysaux Catalog

10 / 20

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

11 / 20

11. Postgres by default has built in connection pooling abilities?

False

True

12 / 20

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

False

True

13 / 20

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

choose 3

indexes

triggers

tables

sequences

14 / 20

14. What is a schema?

Namespace that store all objects of a database

A memory area used to cache data from LRU chains

The name used to refer to a super user account

This is the same as a user in Postgres

15 / 20

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

pg_catalog

pg_system

pg_tables

pg_class

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. What column in system catalogs servers as the Primary Key

oid#

obj

obj#

oid

18 / 20

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

pg_symlinks

pg_tabspace

pg_tablespace

pg_tblspc

19 / 20

19. Users should not modify the template0 database

True

False

20 / 20

20. What is the purpose of the postgres database?

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

No such database

regular database that you can use at your discretion

a template for all the other database

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?

True

False

2 / 10

2. The SQL standard specifies three isolation levels?

True

False

3 / 10

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

reading data direct from memory using pg_dirt

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

4 / 10

4. 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 and commits the change.

A transaction reads one and the same row twice, another transaction modifies this row between these reads issue a rollback.

5 / 10

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

choose 3

Read Committed

Serializable

Repeatable Read

Read Uncommitted

6 / 10

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

False

True

7 / 10

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

True

False

8 / 10

8. Which parameters sets the database default isolation level?

default_transaction_isolation

active_transaction_isolation

default_isolation_level

transaction_isolation_level

9 / 10

9. 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 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

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

10 / 10

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

False

True

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. In Postgres, tables are often referred to as which of the below?

view

clog

dump

heap

2 / 10

2. CLOG contains how many bits for each transaction?

3 / 10

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

False

True

4 / 10

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

DELETE

INSERT

CREATE

COMMIT

5 / 10

5. UPDATE can be regarded as which 2 separate operations?

MERGE

DELETE

COMMIT

INSERT

6 / 10

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

False

True

7 / 10

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

False

True

8 / 10

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

False

True

9 / 10

9. The page Special Space is located at the start of the page with highest address

True

False

10 / 10

10. When a transaction is committed Postgres uses a special <replace with answer> structure?

archive log

commit log

redo log

transaction log

Your score is

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