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. Which of below are predefined schemas?

choose 3

pg_toast

pg_schema

pg_temp

information_schema

2 / 20

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

True

False

3 / 20

3. Which of below are predefined schemas?

choose 2

system

public

pg_catalog

postgres

4 / 20

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

True

False

5 / 20

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

True

False

6 / 20

6. The information_schema schema provides information on Postgres release notes?

True

False

7 / 20

7. To understand each other, a client and a server must use one and the same interfacing protocol?

False

True

8 / 20

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

System Catalog

Sysasm Catalog

Sysaux Catalog

Sys Catalog

9 / 20

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

True

False

10 / 20

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

11 / 20

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

online redo logs (ORL)

rollback segments (RBS)

undo segments (UNDO)

write-ahead log (WAL)

12 / 20

12. What is the purpose of the public schema?

default schema for user objects

schema used for heterogeneous replication

no such schema

restricted schema for postgres internal usage only

13 / 20

13. Users should not modify the template0 database

True

False

14 / 20

14. What is the purpose of the template1 database?

No such database

a template for all the other databases

regular database that you can use at your discretion

database used for temporary tables

15 / 20

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

5MB

1MB

1GB

5GB

16 / 20

16. Which fork is specific for unlogged tables?

visiblilty map

Main fork

Initialization fork

free space map

17 / 20

17. What is the purpose of autovacuum?

Deletes old logs and traces on disk

Rebuilds indexes with b level greater than 2

Removes stale data from tables and indexes

Performs a backup of WAL logs

18 / 20

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

PGCORE

PGBASE

PGTIPS

PGDATA

19 / 20

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

False

True

20 / 20

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

True

False

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. Which parameters sets the database default isolation level?

transaction_isolation_level

default_transaction_isolation

active_transaction_isolation

default_isolation_level

2 / 10

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

Select more than 1 answer below:

Apply explicit locks

Replace procedural code with declarative one.

Use a single SQL operator

Issues a rollback after the commit to satisfy repeatable read.

3 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

4 / 10

4. 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 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

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.

5 / 10

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

False

True

6 / 10

6. What is the default Isolation Level?

Serializable

Repeatable Read

Read Committed

Read Uncommitted

7 / 10

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

False

True

8 / 10

8. The SQL standard specifies three isolation levels?

False

True

9 / 10

9. 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.

10 / 10

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

choose 3

Read Uncommitted

Repeatable Read

Serializable

Read Committed

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. If a transaction aborts, all page changes are reverted(rolled back) in place?

True

False

2 / 10

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

pageinspect

pageheadinfo

pagesize

pagedetect

3 / 10

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

redo log

transaction log

archive log

commit log

4 / 10

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

True

False

5 / 10

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

INSERT

DELETE

CREATE

COMMIT

6 / 10

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

xid

xmas

xmin

xmax

7 / 10

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

False

True

8 / 10

8. CLOG contains how many bits for each transaction?

9 / 10

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

False

True

10 / 10

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

True

False

Your score is

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