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

2 / 20

2. 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

3 / 20

3. What is another name for the postgres process?

masterprocess

postmaster

postmanager

aurora

4 / 20

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

False

True

5 / 20

5. Users should not modify the template0 database

False

True

6 / 20

6. What is the purpose of wal writer?

flushes dirty pages to disk.

executes checkpoints

writes WAL entries to disk

collects usage statistics for the instance.

7 / 20

7. What 3 files/forks as a minimum make up a table on disk?

visiblilty map

table map

free space map

Main fork

8 / 20

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

pg_symlinks

pg_tabspace

pg_tablespace

pg_tblspc

9 / 20

9. TOAST tables reside in a seperate schema?

False

True

10 / 20

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

True

False

11 / 20

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

True

False

12 / 20

12. Tablespaces are used to define physical data layout?

False

True

13 / 20

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

BREAD

GROW

BAKE

TOAST

14 / 20

14. What is the purpose of autovacuum?

Rebuilds indexes with b level greater than 2

Deletes old logs and traces on disk

Removes stale data from tables and indexes

Performs a backup of WAL logs

15 / 20

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

True

False

16 / 20

16. Which fork is specific for unlogged tables?

Main fork

visiblilty map

Initialization fork

free space map

17 / 20

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

False

True

18 / 20

18. Which of below are predefined schemas?

choose 3

pg_toast

pg_temp

information_schema

pg_schema

19 / 20

19. System Catalog tables begin with which prefix?

pg_

dba_

sys_

cat_

20 / 20

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

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. The SQL standard specifies three isolation levels?

True

False

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.

Issues a rollback after the commit to satisfy repeatable read.

Use a single SQL operator

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.

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.

4 / 10

4. 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.

5 / 10

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

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

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

reading data direct from memory using pg_dirt

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

6 / 10

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

True

False

7 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

8 / 10

8. Which of the below are valid Isolations Levels?

choose 2

Read Committed

Random Scatter

Rollback Read

Serializable

9 / 10

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

False

True

10 / 10

10. What is the default Isolation Level?

Repeatable Read

Serializable

Read Committed

Read Uncommitted

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. CLOG Pages are never cached in memory?

True

False

2 / 10

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

heap

view

dump

clog

3 / 10

3. Tuples can also be referred to as columns?

False

True

4 / 10

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

pg_current_commit_id()

pg_current_id()

pg_current_xmin_id()

pg_current_xact_id()

5 / 10

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

True

False

6 / 10

6. Information about subtransactions is stored under?

PGDATA/pg_min

PGDATA/pg_xid

PGDATA/pg_subtrans

PGDATA/subtrans

7 / 10

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

False

True

8 / 10

8. Each page has a layer that usually consists of?

choose 2

undo segment

page header

flashback block

free space

9 / 10

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

False

True

10 / 10

10. index row headers like table row headers contain xmin and xmax fields?

True

False

Your score is

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