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 fork is specific for unlogged tables?

Main fork

visiblilty map

free space map

Initialization fork

2 / 20

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

True

False

3 / 20

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

True

False

4 / 20

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

PGCORE

PGDATA

PGBASE

PGTIPS

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

choose 2

pg_default

pg_tablespace

pg_global

pg_temp

7 / 20

7. What is the point of the pg_global tablespace?

stores temporary tables that are common to the whole cluster

stores user 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

8 / 20

8. System Catalog tables begin with which prefix?

pg_

sys_

dba_

cat_

9 / 20

9. What is another name for the postgres process?

postmaster

aurora

masterprocess

postmanager

10 / 20

10. What is the purpose of wal writer?

writes WAL entries to disk

flushes dirty pages to disk.

executes checkpoints

collects usage statistics for the instance.

11 / 20

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

CreateCluster

Initialize

CreatePGC

StartNewPG

12 / 20

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

pg_symlinks

pg_tblspc

pg_tabspace

pg_tablespace

13 / 20

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

True

False

14 / 20

14. TOAST tables reside in a seperate schema?

True

False

15 / 20

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

False

True

16 / 20

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

False

True

17 / 20

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

oid

obj#

obj

oid#

18 / 20

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

rollback segments (RBS)

online redo logs (ORL)

undo segments (UNDO)

write-ahead log (WAL)

19 / 20

19. Which fork contains the actual table data?

Main fork

visiblilty map

table map

free space map

20 / 20

20. What is the purpose of the template0 database?

No such database

Useful for Postgres support Services to debug issues

Useful for creating development schemas

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

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

Read Committed

Repeatable Read

Read Uncommitted

Serializable

3 / 10

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

reading data direct from memory using pg_dirt

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

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

4 / 10

4. 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

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.

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

5 / 10

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

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

6 / 10

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

7 / 10

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

False

True

8 / 10

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

True

False

9 / 10

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

SAFE

SOC2

HIPPA

ACID

10 / 10

10. What is the default Isolation Level?

Read Committed

Repeatable Read

Serializable

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. If a transaction aborts, all page changes are reverted(rolled back) in place?

False

True

2 / 10

2. When a transaction is committed Postgres uses a special <replace with answer> structure?

redo log

transaction log

archive log

commit log

3 / 10

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

False

True

4 / 10

4. Which of the below are true about a Pages Item Pointer?

stored in PGDATA/itemptr directory

Also know as the pages table of contents

Each pointer uses 4 bytes

Each pointer uses 8 bytes

5 / 10

5. Which 2 of the below represent transaction IDs used for row versioning?

xtime

xmin

xmax

xid

6 / 10

6. status of a subtransaction is written into CLOG?

False

True

7 / 10

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

True

False

8 / 10

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

True

False

9 / 10

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

sequential number

checksum

xmin

backend process ID

10 / 10

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

False

True

Your score is

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