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. How many rows in a page does Postgres aim to have before considering TOAST?

2 / 20

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

True

False

3 / 20

3. What is the purpose of wal writer?

executes checkpoints

collects usage statistics for the instance.

writes WAL entries to disk

flushes dirty pages to disk.

4 / 20

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

pg_symlinks

pg_tabspace

pg_tblspc

pg_tablespace

5 / 20

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

Directory Path

Access Path

Search Path

Schema Path

6 / 20

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

pg_class

pg_catalog

pg_system

pg_tables

7 / 20

7. System Catalog tables begin with which prefix?

pg_

sys_

dba_

cat_

8 / 20

8. What is a schema?

Namespace that store all objects of a database

This is the same as a user in Postgres

The name used to refer to a super user account

A memory area used to cache data from LRU chains

9 / 20

9. TOAST tables reside in a seperate schema?

True

False

10 / 20

10. Which of below are predefined schemas?

choose 3

information_schema

pg_schema

pg_temp

pg_toast

11 / 20

11. What is the purpose of the postgres database?

No such database

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

a template for all the other database

regular database that you can use at your discretion

12 / 20

12. What is the point of the pg_global tablespace?

stores user tables that are common to the whole cluster

stores temporary tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

stores WAL logs used for global replication

13 / 20

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

True

False

14 / 20

14. What column in system catalogs servers as the Primary Key

obj

oid

oid#

obj#

15 / 20

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

5GB

1MB

5MB

1GB

16 / 20

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

True

False

17 / 20

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

True

False

18 / 20

18. What is the purpose of autovacuum?

Performs a backup of WAL logs

Removes stale data from tables and indexes

Rebuilds indexes with b level greater than 2

Deletes old logs and traces on disk

19 / 20

19. Which fork is specific for unlogged tables?

Initialization fork

Main fork

visiblilty map

free space map

20 / 20

20. Tablespaces can be used to segregate data based on performance needs?

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

SAFE

ACID

HIPPA

SOC2

2 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

3 / 10

3. What is the default Isolation Level?

Read Uncommitted

Read Committed

Serializable

Repeatable Read

4 / 10

4. 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.

Use a single SQL operator

Apply explicit locks

Issues a rollback after the commit to satisfy repeatable read.

5 / 10

5. Which of the below are valid Isolations Levels?

choose 2

Random Scatter

Serializable

Read Committed

Rollback Read

6 / 10

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

False

True

7 / 10

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

True

False

8 / 10

8. Which isolation level in theory could mean an application does not have to consider isolation anomalies?

Read Uncommitted

Serializable

Repeatable Read

Read Committed

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

10 / 10

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

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

False

True

2 / 10

2. indexes do not use row versioning?

False

True

3 / 10

3. CLOG Pages are never cached in memory?

False

True

4 / 10

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

False

True

5 / 10

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

pagedetect

pagesize

pageinspect

pageheadinfo

6 / 10

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

xmin

xid

xmas

xmax

7 / 10

7. If a transaction is read only which kind of Transaction ID is it allocated?

heap XID

magic XID

virtual XID

temporary XID

8 / 10

8. Postgres table physical data files are always cross compatible across platforms?

False

True

9 / 10

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

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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