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 of the below objects can be referred to as relations?

choose 3

tables

indexes

triggers

sequences

2 / 20

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

False

True

3 / 20

3. Tablespaces are used to define physical data layout?

False

True

4 / 20

4. What is the purpose of wal writer?

collects usage statistics for the instance.

writes WAL entries to disk

flushes dirty pages to disk.

executes checkpoints

5 / 20

5. What is the purpose of the template0 database?

Useful for Postgres support Services to debug issues

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

Useful for creating development schemas

No such database

6 / 20

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

Access Path

Search Path

Schema Path

Directory Path

7 / 20

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

System Catalog

Sysasm Catalog

Sys Catalog

Sysaux Catalog

8 / 20

8. Each Database has its own System Catalog?

False

True

9 / 20

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

False

True

10 / 20

10. What is the purpose of autovacuum?

Deletes old logs and traces on disk

Performs a backup of WAL logs

Rebuilds indexes with b level greater than 2

Removes stale data from tables and indexes

11 / 20

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

True

False

12 / 20

12. What is the purpose of the public schema?

no such schema

schema used for heterogeneous replication

default schema for user objects

restricted schema for postgres internal usage only

13 / 20

13. 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

14 / 20

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

True

False

15 / 20

15. A Postgres cluster consists of 2 or more physical servers accessing one Postgres Instance?

True

False

16 / 20

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

Dan Brown

Egor Rogov

Sam Altman

Paul Sammy

17 / 20

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

1MB

5MB

1GB

5GB

18 / 20

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

Choose 2 option

Postgres Server

Instance

Aurora

Quorum

19 / 20

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

True

False

20 / 20

20. Which fork keeps track of available space within pages?

free space map

used space map

wal space map

vacuum space map

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

choose 3

Read Uncommitted

Read Committed

Serializable

Repeatable Read

2 / 10

2. 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 twice, another transaction modifies this row between these reads 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 once and modifies this row and commits the change.

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 are valid Isolations Levels?

choose 2

Rollback Read

Read Committed

Random Scatter

Serializable

5 / 10

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

Read Uncommitted

Read Committed

Serializable

Repeatable Read

6 / 10

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

False

True

7 / 10

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

ALTER SYSTEM SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

8 / 10

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

Select more than 1 answer below:

Use a single SQL operator

Replace procedural code with declarative one.

Apply explicit locks

Issues a rollback after the commit to satisfy repeatable read.

9 / 10

9. Which parameters sets the database default isolation level?

default_transaction_isolation

default_isolation_level

transaction_isolation_level

active_transaction_isolation

10 / 10

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

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. Which 2 items does a Virtual XID consist of?

sequential number

xmin

backend process ID

checksum

2 / 10

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

xmax

xmin

xmas

xid

3 / 10

3. Information about subtransactions is stored under?

PGDATA/pg_subtrans

PGDATA/subtrans

PGDATA/pg_xid

PGDATA/pg_min

4 / 10

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

redo log

archive log

commit log

transaction log

5 / 10

5. Tuples can also be referred to as columns?

True

False

6 / 10

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

False

True

7 / 10

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

DELETE

COMMIT

CREATE

INSERT

8 / 10

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

False

True

9 / 10

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

True

False

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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