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 purpose of the public schema?

restricted schema for postgres internal usage only

default schema for user objects

no such schema

schema used for heterogeneous replication

2 / 20

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

True

False

3 / 20

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

Search Path

Schema Path

Access Path

Directory Path

4 / 20

4. Users should not modify the template0 database

False

True

5 / 20

5. What is the point of the pg_global tablespace?

stores system catalog objects that are common to the whole cluster

stores temporary tables that are common to the whole cluster

stores user tables that are common to the whole cluster

stores WAL logs used for global replication

6 / 20

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

undo segments (UNDO)

rollback segments (RBS)

write-ahead log (WAL)

online redo logs (ORL)

7 / 20

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

obj

obj#

oid#

oid

8 / 20

8. What is the purpose of the template0 database?

Useful for creating development schemas

No such database

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

Useful for Postgres support Services to debug issues

9 / 20

9. Tablespaces are used to define physical data layout?

True

False

10 / 20

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

True

False

11 / 20

11. Which of below are predefined schemas?

choose 2

system

pg_catalog

postgres

public

12 / 20

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

True

False

13 / 20

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

Sys Catalog

System Catalog

Sysasm Catalog

Sysaux Catalog

14 / 20

14. What is the purpose of the postgres database?

regular database that you can use at your discretion

a template for all the other database

No such database

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

15 / 20

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

True

False

16 / 20

16. TOAST tables reside in a seperate schema?

False

True

17 / 20

17. How many files or forks on disk will a 10Mb table with no index have?

18 / 20

18. Which 3 databases exist directly after cluster initialization?

choose 3 options

template0

template1

postgres

sysaux

19 / 20

19. Postgres uses a thread based process model?

True

False

20 / 20

20. 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

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

2 / 10

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

choose 3

Read Committed

Read Uncommitted

Repeatable Read

Serializable

3 / 10

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

SAFE

SOC2

HIPPA

ACID

4 / 10

4. Which parameters sets the database default isolation level?

transaction_isolation_level

default_transaction_isolation

default_isolation_level

active_transaction_isolation

5 / 10

5. The SQL standard specifies three isolation levels?

True

False

6 / 10

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

Repeatable Read

Read Committed

Serializable

Read Uncommitted

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 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.

A transaction reads one and the same row twice, another transaction modifies this row between these reads and commits the change.

8 / 10

8. 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.

Use a single SQL operator

Replace procedural code with declarative one.

Apply explicit locks

9 / 10

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

True

False

10 / 10

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

True

False

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

True

False

2 / 10

2. Information about subtransactions is stored under?

PGDATA/pg_subtrans

PGDATA/subtrans

PGDATA/pg_xid

PGDATA/pg_min

3 / 10

3. Indexes values also support multi versioning with several versions of an index value existing at any point in time?

True

False

4 / 10

4. status of a subtransaction is written into CLOG?

False

True

5 / 10

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

sequential number

checksum

backend process ID

xmin

6 / 10

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

True

False

7 / 10

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

temporary XID

virtual XID

magic XID

heap XID

8 / 10

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

True

False

9 / 10

9. Page header sizes can be easily displayed using the <choose from answers> extension

pagesize

pageheadinfo

pagedetect

pageinspect

10 / 10

10. indexes do not use row versioning?

True

False

Your score is

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