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. Files are logically split into pages?

True

False

2 / 20

2. Postgres uses a thread based process model?

True

False

3 / 20

3. Tablespaces are used to define physical data layout?

False

True

4 / 20

4. What is the purpose of the postgres database?

No such database

a template for all the other database

regular database that you can use at your discretion

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

5 / 20

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

TOAST

GROW

BAKE

BREAD

6 / 20

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

oid

obj

obj#

oid#

7 / 20

7. What is the purpose of the template1 database?

database used for temporary tables

regular database that you can use at your discretion

No such database

a template for all the other databases

8 / 20

8. What is a schema?

A memory area used to cache data from LRU chains

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

9 / 20

9. What is the purpose of wal writer?

writes WAL entries to disk

flushes dirty pages to disk.

collects usage statistics for the instance.

executes checkpoints

10 / 20

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

True

False

11 / 20

11. System Catalog tables begin with which prefix?

pg_

dba_

cat_

sys_

12 / 20

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

pg_tables

pg_system

pg_catalog

pg_class

13 / 20

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

pg_symlinks

pg_tabspace

pg_tblspc

pg_tablespace

14 / 20

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

CreatePGC

CreateCluster

StartNewPG

Initialize

15 / 20

15. What is the point of the pg_global tablespace?

stores temporary tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

stores user tables that are common to the whole cluster

stores WAL logs used for global replication

16 / 20

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

False

True

17 / 20

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

1MB

5MB

5GB

1GB

18 / 20

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

False

True

19 / 20

19. Users should not modify the template0 database

True

False

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

False

True

2 / 10

2. A phantom read anomaly occurs when?

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 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 also queries this same data.

3 / 10

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

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

reading data direct from memory using pg_dirt

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

4 / 10

4. The more locks a transaction acquires, the better it is isolated from other transactions?

False

True

5 / 10

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

Select more than 1 answer below:

Issues a rollback after the commit to satisfy repeatable read.

Apply explicit locks

Replace procedural code with declarative one.

Use a single SQL operator

6 / 10

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

True

False

7 / 10

7. 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.

8 / 10

8. What is the default Isolation Level?

Repeatable Read

Read Committed

Serializable

Read Uncommitted

9 / 10

9. The SQL standard specifies three isolation levels?

True

False

10 / 10

10. 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;

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?

MERGE

COMMIT

DELETE

INSERT

2 / 10

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

CREATE

DELETE

INSERT

COMMIT

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

False

True

5 / 10

5. Tuples can also be referred to as columns?

False

True

6 / 10

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

temporary XID

heap XID

virtual XID

magic XID

7 / 10

7. The page header is located in the highest address?

False

True

8 / 10

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

True

False

9 / 10

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

False

True

10 / 10

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

True

False

Your score is

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