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. Postgres by default has built in connection pooling abilities?

True

False

2 / 20

2. What is the purpose of the visibility map?

shows a page to be vacuumed or frozen

provides an audit trail for the database

shows referential relationships for tables

provides the data decryption key

3 / 20

3. What is the purpose of the template1 database?

No such database

regular database that you can use at your discretion

database used for temporary tables

a template for all the other databases

4 / 20

4. Tablespaces are used to define physical data layout?

False

True

5 / 20

5. What is the purpose of wal writer?

executes checkpoints

collects usage statistics for the instance.

writes WAL entries to disk

flushes dirty pages to disk.

6 / 20

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

False

True

7 / 20

7. Which fork contains the actual table data?

free space map

Main fork

visiblilty map

table map

8 / 20

8. Files are logically split into pages?

False

True

9 / 20

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

10 / 20

10. Postgres uses a thread based process model?

False

True

11 / 20

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

1GB

1MB

5GB

5MB

12 / 20

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

oid#

oid

obj#

obj

13 / 20

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

False

True

14 / 20

14. Users should not modify the template0 database

True

False

15 / 20

15. What is a schema?

Namespace that store all objects of a database

The name used to refer to a super user account

This is the same as a user in Postgres

A memory area used to cache data from LRU chains

16 / 20

16. 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

17 / 20

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

Egor Rogov

Paul Sammy

Sam Altman

Dan Brown

18 / 20

18. What is another name for the postgres process?

postmanager

postmaster

masterprocess

aurora

19 / 20

19. What is the purpose of autovacuum?

Performs a backup of WAL logs

Rebuilds indexes with b level greater than 2

Deletes old logs and traces on disk

Removes stale data from tables and indexes

20 / 20

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

False

True

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

False

True

2 / 10

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

ACID

SOC2

SAFE

HIPPA

3 / 10

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

True

False

4 / 10

4. 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.

5 / 10

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

False

True

6 / 10

6. Which of the below are valid Isolations Levels?

choose 2

Rollback Read

Serializable

Read Committed

Random Scatter

7 / 10

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

False

True

8 / 10

8. The SQL standard specifies three isolation levels?

False

True

9 / 10

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

False

True

10 / 10

10. 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 also queries this same data.

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 adds some other rows satisfying this condition and commits.

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 of the below are true about a Pages Item Pointer?

Also know as the pages table of contents

Each pointer uses 4 bytes

Each pointer uses 8 bytes

stored in PGDATA/itemptr directory

2 / 10

2. What does an Item Pointer contain?

choose 3

tuple status

tuple length

tuple xid

tuple offset from the start of the page

3 / 10

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

xmin

xmas

xmax

xid

4 / 10

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

False

True

5 / 10

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

False

True

6 / 10

6. Information about subtransactions is stored under?

PGDATA/pg_min

PGDATA/pg_xid

PGDATA/pg_subtrans

PGDATA/subtrans

7 / 10

7. Each page has a layer that usually consists of?

choose 2

undo segment

page header

free space

flashback block

8 / 10

8. Which 2 of the below represent transaction IDs used for row versioning?

xmax

xmin

xid

xtime

9 / 10

9. CLOG contains how many bits for each transaction?

10 / 10

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

xmin

checksum

sequential number

backend process ID

Your score is

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