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 the below objects can be referred to as relations?

choose 3

sequences

indexes

tables

triggers

2 / 20

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

True

False

3 / 20

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

Sysasm Catalog

Sys Catalog

Sysaux Catalog

System Catalog

4 / 20

4. Which fork contains the actual table data?

visiblilty map

table map

Main fork

free space map

5 / 20

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

False

True

6 / 20

6. System Catalog tables begin with which prefix?

cat_

sys_

dba_

pg_

7 / 20

7. Tablespaces are used to define physical data layout?

True

False

8 / 20

8. What is the purpose of wal writer?

flushes dirty pages to disk.

collects usage statistics for the instance.

writes WAL entries to disk

executes checkpoints

9 / 20

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

pg_class

pg_catalog

pg_system

pg_tables

10 / 20

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

False

True

11 / 20

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

1MB

1GB

5GB

5MB

12 / 20

12. TOAST tables reside in a seperate schema?

False

True

13 / 20

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

14 / 20

14. What is another name for the postgres process?

postmaster

masterprocess

postmanager

aurora

15 / 20

15. The default Page size is 2k?

True

False

16 / 20

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

17 / 20

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

pg_tablespace

pg_tabspace

pg_tblspc

pg_symlinks

18 / 20

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

False

True

19 / 20

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

Access Path

Directory Path

Schema Path

Search Path

20 / 20

20. Postgres uses a thread based process model?

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. 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.

2 / 10

2. 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

Issues a rollback after the commit to satisfy repeatable read.

Apply explicit locks

Replace procedural code with declarative one.

3 / 10

3. 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.

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

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

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.

4 / 10

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

SOC2

HIPPA

ACID

SAFE

5 / 10

5. Which parameters sets the database default isolation level?

default_isolation_level

active_transaction_isolation

transaction_isolation_level

default_transaction_isolation

6 / 10

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

False

True

7 / 10

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

choose 3

Read Uncommitted

Read Committed

Repeatable Read

Serializable

8 / 10

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

True

False

9 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

10 / 10

10. Which of the below would best describe a dirty read?

a session being able to see uncommited data altered by another session

reading the data directly from file using a text editor such as vi or notepad

reading data direct from memory using pg_dirt

a session being able to see commited data altered by another session

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. indexes do not use row versioning?

False

True

2 / 10

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

True

False

3 / 10

3. Indexes values also support multi versioning with several versions of an index value existing at any point in time?

False

True

4 / 10

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

view

clog

heap

dump

5 / 10

5. CLOG Pages are never cached in memory?

False

True

6 / 10

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

xmin

sequential number

backend process ID

checksum

7 / 10

7. Information about subtransactions is stored under?

PGDATA/pg_subtrans

PGDATA/subtrans

PGDATA/pg_min

PGDATA/pg_xid

8 / 10

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

True

False

9 / 10

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

True

False

10 / 10

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

INSERT

CREATE

COMMIT

DELETE

Your score is

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