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. What is the point of the pg_global tablespace?

stores WAL logs used for global replication

stores user tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

stores temporary tables that are common to the whole cluster

2 / 20

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

rollback segments (RBS)

write-ahead log (WAL)

undo segments (UNDO)

online redo logs (ORL)

3 / 20

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

True

False

4 / 20

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

False

True

5 / 20

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

False

True

6 / 20

6. What is the purpose of the visibility map?

provides an audit trail for the database

provides the data decryption key

shows referential relationships for tables

shows a page to be vacuumed or frozen

7 / 20

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

pg_tabspace

pg_symlinks

pg_tblspc

pg_tablespace

8 / 20

8. What is another name for the postgres process?

postmanager

postmaster

masterprocess

aurora

9 / 20

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

PGDATA

PGCORE

PGTIPS

PGBASE

10 / 20

10. What is the purpose of the postgres database?

regular database that you can use at your discretion

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

a template for all the other database

No such database

11 / 20

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

True

False

12 / 20

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

False

True

13 / 20

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

Access Path

Search Path

Directory Path

Schema Path

14 / 20

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

CreatePGC

CreateCluster

StartNewPG

Initialize

15 / 20

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

16 / 20

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

5MB

1GB

5GB

1MB

17 / 20

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

vacuum space map

free space map

used space map

wal space map

18 / 20

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

True

False

19 / 20

19. Which fork contains the actual table data?

visiblilty map

Main fork

free space map

table map

20 / 20

20. When PostgreSQL is running what can it be referred to as?

Choose 2 option

Aurora

Quorum

Instance

Postgres Server

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

True

False

2 / 10

2. 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 twice, another transaction modifies this row between these reads issue a rollback.

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

3 / 10

3. Which of the below are valid Isolations Levels?

choose 2

Rollback Read

Random Scatter

Serializable

Read Committed

4 / 10

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

choose 3

Serializable

Read Committed

Read Uncommitted

Repeatable Read

5 / 10

5. 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.

6 / 10

6. 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.

7 / 10

7. 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;

8 / 10

8. Which parameters sets the database default isolation level?

default_transaction_isolation

default_isolation_level

active_transaction_isolation

transaction_isolation_level

9 / 10

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

True

False

10 / 10

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

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. What does an Item Pointer contain?

choose 3

tuple xid

tuple status

tuple length

tuple offset from the start of the page

2 / 10

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

backend process ID

checksum

sequential number

xmin

3 / 10

3. Page free space can often become fragmented?

False

True

4 / 10

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

xmin

xmas

xid

xmax

5 / 10

5. Information about subtransactions is stored under?

PGDATA/pg_min

PGDATA/pg_xid

PGDATA/pg_subtrans

PGDATA/subtrans

6 / 10

6. CLOG files are stored in which directory?

PGDATA/pg_xact

PGDATA/pg_clog

PGDATA/pg_commit

PGDATA/clog

7 / 10

7. a transaction containing a savepoint is will still be considered as only a single transaction?

True

False

8 / 10

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

False

True

9 / 10

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

pagedetect

pageinspect

pageheadinfo

pagesize

10 / 10

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

False

True

Your score is

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