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 2 default tablespaces created after initialization?

choose 2

pg_global

pg_tablespace

pg_default

pg_temp

2 / 20

2. What is the purpose of the visibility map?

provides the data decryption key

shows referential relationships for tables

provides an audit trail for the database

shows a page to be vacuumed or frozen

3 / 20

3. When PostgreSQL is running what can it be referred to as?

Choose 2 option

Instance

Quorum

Postgres Server

Aurora

4 / 20

4. 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.

5 / 20

5. Which fork contains the actual table data?

Main fork

free space map

table map

visiblilty map

6 / 20

6. What is the purpose of the template0 database?

Useful for creating development schemas

Useful for Postgres support Services to debug issues

No such database

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

7 / 20

7. The default Page size is 2k?

False

True

8 / 20

8. What is a schema?

This is the same as a user in Postgres

A memory area used to cache data from LRU chains

Namespace that store all objects of a database

The name used to refer to a super user account

9 / 20

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

False

True

10 / 20

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

True

False

11 / 20

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

oid

obj

oid#

obj#

12 / 20

12. What is the purpose of the public schema?

no such schema

schema used for heterogeneous replication

restricted schema for postgres internal usage only

default schema for user objects

13 / 20

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

Directory Path

Schema Path

Access Path

Search Path

14 / 20

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

postman

pginit

postgres

init

15 / 20

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

1GB

5GB

5MB

1MB

16 / 20

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

True

False

17 / 20

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

Main fork

free space map

table map

visiblilty map

18 / 20

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

Paul Sammy

Sam Altman

Dan Brown

Egor Rogov

19 / 20

19. Files are logically split into pages?

False

True

20 / 20

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

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

False

True

2 / 10

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

True

False

3 / 10

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

True

False

4 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

5 / 10

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

False

True

6 / 10

6. The SQL standard specifies three isolation levels?

False

True

7 / 10

7. non-repeatable read anomaly occurs when?

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.

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.

8 / 10

8. A phantom read anomaly occurs when?

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

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.

9 / 10

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

True

False

10 / 10

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

choose 3

Read Committed

Read Uncommitted

Serializable

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

False

True

2 / 10

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

False

True

3 / 10

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

commit log

archive log

transaction log

redo log

4 / 10

4. UPDATE can be regarded as which 2 separate operations?

MERGE

INSERT

COMMIT

DELETE

5 / 10

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

False

True

6 / 10

6. CLOG files are stored in which directory?

PGDATA/pg_commit

PGDATA/pg_clog

PGDATA/pg_xact

PGDATA/clog

7 / 10

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

False

True

8 / 10

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

False

True

9 / 10

9. To identify different versions of one and the same row, PostgreSQL marks each of them with which two value?

xmin

xmas

xmax

xid

10 / 10

10. Tuples can also be referred to as columns?

True

False

Your score is

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