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 column in system catalogs servers as the Primary Key

obj#

oid#

oid

obj

2 / 20

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

Access Path

Directory Path

Search Path

Schema Path

3 / 20

3. What is the name of the system catalog table for relations?

pg_catalog

pg_tables

pg_system

pg_class

4 / 20

4. What is a schema?

A memory area used to cache data from LRU chains

This is the same as a user in Postgres

The name used to refer to a super user account

Namespace that store all objects of a database

5 / 20

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

6 / 20

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

postman

postgres

init

pginit

7 / 20

7. TOAST tables reside in a seperate schema?

True

False

8 / 20

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

True

False

9 / 20

9. What is the purpose of the template1 database?

a template for all the other databases

regular database that you can use at your discretion

database used for temporary tables

No such database

10 / 20

10. System Catalog tables begin with which prefix?

pg_

cat_

sys_

dba_

11 / 20

11. What is the name of the mechanism used to store a row bigger than a page size?

BAKE

GROW

TOAST

BREAD

12 / 20

12. What is the purpose of the postgres database?

a template for all the other database

No such database

regular database that you can use at your discretion

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

13 / 20

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

undo segments (UNDO)

rollback segments (RBS)

write-ahead log (WAL)

online redo logs (ORL)

14 / 20

14. Users should not modify the template0 database

True

False

15 / 20

15. Postgres server spawns a new backend session for each connection?

True

False

16 / 20

16. What is the purpose of the public schema?

schema used for heterogeneous replication

restricted schema for postgres internal usage only

no such schema

default schema for user objects

17 / 20

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

True

False

18 / 20

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

choose 2

pg_global

pg_tablespace

pg_temp

pg_default

19 / 20

19. Files are logically split into pages?

False

True

20 / 20

20. What is another name for the postgres process?

postmaster

postmanager

masterprocess

aurora

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. non-repeatable read anomaly occurs when?

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

2 / 10

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

True

False

3 / 10

3. The SQL standard specifies three isolation levels?

True

False

4 / 10

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

Read Uncommitted

Read Committed

Serializable

Repeatable Read

5 / 10

5. A phantom read anomaly occurs when?

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.

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

6 / 10

6. What is the default Isolation Level?

Read Uncommitted

Serializable

Read Committed

Repeatable Read

7 / 10

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

False

True

8 / 10

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

True

False

9 / 10

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

SAFE

SOC2

ACID

HIPPA

10 / 10

10. 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.

Replace procedural code with declarative one.

Apply explicit locks

Use a single SQL operator

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

virtual XID

temporary XID

magic XID

heap XID

2 / 10

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

backend process ID

sequential number

checksum

xmin

3 / 10

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

False

True

4 / 10

4. CLOG files are stored in which directory?

PGDATA/clog

PGDATA/pg_xact

PGDATA/pg_commit

PGDATA/pg_clog

5 / 10

5. Page free space can often become fragmented?

False

True

6 / 10

6. indexes do not use row versioning?

False

True

7 / 10

7. What does an Item Pointer contain?

choose 3

tuple offset from the start of the page

tuple status

tuple xid

tuple length

8 / 10

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

True

False

9 / 10

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

pg_current_xmin_id()

pg_current_id()

pg_current_xact_id()

pg_current_commit_id()

10 / 10

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

True

False

Your score is

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