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 column in system catalogs servers as the Primary Key

obj

oid#

oid

obj#

2 / 20

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

True

False

3 / 20

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

True

False

4 / 20

4. What is the process first launched at server start?

init

postgres

pginit

postman

5 / 20

5. What is the purpose of the postgres database?

No such database

regular database that you can use at your discretion

a template for all the other database

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

6 / 20

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

Search Path

Schema Path

Directory Path

Access Path

7 / 20

7. TOAST tables reside in a seperate schema?

True

False

8 / 20

8. What is the purpose of the public schema?

restricted schema for postgres internal usage only

default schema for user objects

schema used for heterogeneous replication

no such schema

9 / 20

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

Sys Catalog

System Catalog

Sysasm Catalog

Sysaux Catalog

10 / 20

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

GROW

TOAST

BAKE

BREAD

11 / 20

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

False

True

12 / 20

12. Users should not modify the template0 database

False

True

13 / 20

13. What is the purpose of wal writer?

writes WAL entries to disk

executes checkpoints

flushes dirty pages to disk.

collects usage statistics for the instance.

14 / 20

14. What is the purpose of the template0 database?

Useful for Postgres support Services to debug issues

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

No such database

Useful for creating development schemas

15 / 20

15. Which of below are predefined schemas?

choose 3

pg_toast

pg_schema

information_schema

pg_temp

16 / 20

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

choose 2

pg_default

pg_temp

pg_global

pg_tablespace

17 / 20

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

pg_tblspc

pg_tablespace

pg_tabspace

pg_symlinks

18 / 20

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

StartNewPG

CreateCluster

Initialize

CreatePGC

19 / 20

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

True

False

20 / 20

20. Who is the Author of the Postgres 14 Internals book?

Sam Altman

Dan Brown

Egor Rogov

Paul Sammy

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 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.

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.

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. The SQL standard specifies three isolation levels?

False

True

4 / 10

4. Which of the below are valid Isolations Levels?

choose 2

Read Committed

Rollback Read

Random Scatter

Serializable

5 / 10

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

choose 3

Repeatable Read

Read Committed

Serializable

Read Uncommitted

6 / 10

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

False

True

7 / 10

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

Select more than 1 answer below:

Use a single SQL operator

Replace procedural code with declarative one.

Apply explicit locks

Issues a rollback after the commit to satisfy repeatable read.

8 / 10

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

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.

9 / 10

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

True

False

10 / 10

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

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. UPDATE can be regarded as which 2 separate operations?

INSERT

MERGE

DELETE

COMMIT

2 / 10

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

True

False

3 / 10

3. CLOG Pages are never cached in memory?

False

True

4 / 10

4. Page free space can often become fragmented?

False

True

5 / 10

5. Tuples can also be referred to as columns?

False

True

6 / 10

6. at any one time Postgres can have several versions of a row?

True

False

7 / 10

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

COMMIT

INSERT

CREATE

DELETE

8 / 10

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

pageinspect

pagedetect

pagesize

pageheadinfo

9 / 10

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

False

True

10 / 10

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

pg_current_commit_id()

pg_current_xmin_id()

pg_current_xact_id()

pg_current_id()

Your score is

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