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

Sys Catalog

System Catalog

Sysasm Catalog

Sysaux Catalog

2 / 20

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

init

pginit

postman

postgres

3 / 20

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

False

True

4 / 20

4. What is the point of the pg_global tablespace?

stores WAL logs used for global replication

stores user tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

stores temporary tables that are common to the whole cluster

5 / 20

5. What is the purpose of the visibility map?

provides the data decryption key

shows a page to be vacuumed or frozen

provides an audit trail for the database

shows referential relationships for tables

6 / 20

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

False

True

7 / 20

7. The default Page size is 2k?

False

True

8 / 20

8. What is the purpose of the public schema?

restricted schema for postgres internal usage only

no such schema

schema used for heterogeneous replication

default schema for user objects

9 / 20

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

False

True

10 / 20

10. What is another name for the postgres process?

postmaster

postmanager

masterprocess

aurora

11 / 20

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

choose 2

pg_temp

pg_global

pg_default

pg_tablespace

12 / 20

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

True

False

13 / 20

13. A schema can belong to more than one database?

True

False

14 / 20

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

PGTIPS

PGDATA

PGCORE

PGBASE

15 / 20

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

obj

oid#

obj#

oid

16 / 20

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

Directory Path

Schema Path

Access Path

Search Path

17 / 20

17. System Catalog tables begin with which prefix?

cat_

dba_

sys_

pg_

18 / 20

18. 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.

19 / 20

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

Paul Sammy

Dan Brown

Egor Rogov

Sam Altman

20 / 20

20. What is the purpose of autovacuum?

Deletes old logs and traces on disk

Removes stale data from tables and indexes

Rebuilds indexes with b level greater than 2

Performs a backup of WAL logs

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 of the below are valid Isolations Levels?

choose 2

Rollback Read

Serializable

Read Committed

Random Scatter

3 / 10

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

True

False

4 / 10

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

True

False

5 / 10

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

choose 3

Repeatable Read

Read Uncommitted

Read Committed

Serializable

6 / 10

6. 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 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

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 also queries this same data.

7 / 10

7. What is the default Isolation Level?

Read Committed

Read Uncommitted

Repeatable Read

Serializable

8 / 10

8. 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

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

9 / 10

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

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

10 / 10

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

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. Each page has a layer that usually consists of?

choose 2

page header

undo segment

free space

flashback block

2 / 10

2. The page header stores checksum and the sizes of the other parts of the page?

False

True

3 / 10

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

True

False

4 / 10

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

Each pointer uses 4 bytes

stored in PGDATA/itemptr directory

Each pointer uses 8 bytes

Also know as the pages table of contents

5 / 10

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

False

True

6 / 10

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

heap XID

magic XID

virtual XID

temporary XID

7 / 10

7. psql provides a special mode that allows you to continue a transaction after a failure?

True

False

8 / 10

8. What does an Item Pointer contain?

choose 3

tuple status

tuple xid

tuple length

tuple offset from the start of the page

9 / 10

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

pg_current_xact_id()

pg_current_xmin_id()

pg_current_commit_id()

pg_current_id()

10 / 10

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

True

False

Your score is

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