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. Files are logically split into pages?

False

True

2 / 20

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

Initialize

CreatePGC

StartNewPG

CreateCluster

3 / 20

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

choose 2

pg_global

pg_tablespace

pg_default

pg_temp

4 / 20

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

False

True

5 / 20

5. The default Page size is 2k?

True

False

6 / 20

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

False

True

7 / 20

7. What is the purpose of the visibility map?

provides an audit trail for the database

shows referential relationships for tables

shows a page to be vacuumed or frozen

provides the data decryption key

8 / 20

8. How does Postgres know which schema to use if not specified?

Directory Path

Schema Path

Access Path

Search Path

9 / 20

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

True

False

10 / 20

10. What is the purpose of autovacuum?

Removes stale data from tables and indexes

Deletes old logs and traces on disk

Performs a backup of WAL logs

Rebuilds indexes with b level greater than 2

11 / 20

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

True

False

12 / 20

12. System Catalog tables begin with which prefix?

pg_

dba_

sys_

cat_

13 / 20

13. Which of below are predefined schemas?

choose 2

system

pg_catalog

public

postgres

14 / 20

14. What 3 files/forks as a minimum make up a table on disk?

free space map

table map

visiblilty map

Main fork

15 / 20

15. Which of below are predefined schemas?

choose 3

information_schema

pg_toast

pg_temp

pg_schema

16 / 20

16. The pg_default tablespace should never be used to create user tables?

False

True

17 / 20

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

False

True

18 / 20

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

pg_catalog

pg_tables

pg_system

pg_class

19 / 20

19. Postgres uses a thread based process model?

True

False

20 / 20

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

Sysasm Catalog

System Catalog

Sysaux Catalog

Sys Catalog

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 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.

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

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

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

False

True

4 / 10

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

choose 3

Repeatable Read

Serializable

Read Uncommitted

Read Committed

5 / 10

5. non-repeatable read anomaly occurs when?

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.

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.

6 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

7 / 10

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

HIPPA

ACID

SOC2

SAFE

8 / 10

8. What is the default Isolation Level?

Read Committed

Serializable

Repeatable Read

Read Uncommitted

9 / 10

9. What are some of database features we can use to avoid a non repeatable read?

Select more than 1 answer below:

Replace procedural code with declarative one.

Apply explicit locks

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

10 / 10

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

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

pagedetect

pagesize

pageinspect

pageheadinfo

3 / 10

3. What does an Item Pointer contain?

choose 3

tuple xid

tuple status

tuple offset from the start of the page

tuple length

4 / 10

4. Which function can we use to find the current transaction ID?

pg_current_xmin_id()

pg_current_xact_id()

pg_current_id()

pg_current_commit_id()

5 / 10

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

True

False

6 / 10

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

view

dump

clog

heap

7 / 10

7. CLOG files are stored in which directory?

PGDATA/pg_xact

PGDATA/pg_commit

PGDATA/clog

PGDATA/pg_clog

8 / 10

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

commit log

transaction log

redo log

archive log

9 / 10

9. Page free space can often become fragmented?

True

False

10 / 10

10. Which 2 items does a Virtual XID consist of?

sequential number

checksum

xmin

backend process ID

Your score is

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