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

Users should not modify the template0 database

True

False

2 / 20

Each Database has its own System Catalog?

True

False

3 / 20

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

True

False

4 / 20

pg_catalog schema is used to store system catalog tables?

False

True

5 / 20

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

choose 2

pg_default

pg_tablespace

pg_global

pg_temp

6 / 20

The default Page size is 2k?

False

True

7 / 20

What is the purpose of the public schema?

schema used for heterogeneous replication

restricted schema for postgres internal usage only

default schema for user objects

no such schema

8 / 20

Which of the below objects can be referred to as relations?

choose 3

tables

sequences

triggers

indexes

9 / 20

What is the purpose of wal writer?

collects usage statistics for the instance.

writes WAL entries to disk

executes checkpoints

flushes dirty pages to disk.

10 / 20

What is another name for the postgres process?

aurora

masterprocess

postmaster

postmanager

11 / 20

What is the process first launched at server start?

pginit

init

postman

postgres

12 / 20

To be able to restore data consistency, Postgres maintains

undo segments (UNDO)

write-ahead log (WAL)

rollback segments (RBS)

online redo logs (ORL)

13 / 20

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

14 / 20

Postgres server spawns a new backend session for each connection?

False

True

15 / 20

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

pg_catalog

pg_tables

pg_system

pg_class

16 / 20

Which of below are predefined schemas?

choose 3

information_schema

pg_temp

pg_toast

pg_schema

17 / 20

Postgres by default has built in connection pooling abilities?

True

False

18 / 20

What is the name of the directory that contains the files related to the Postgres cluster?

PGDATA

PGCORE

PGBASE

PGTIPS

19 / 20

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

Sys Catalog

Sysasm Catalog

System Catalog

Sysaux Catalog

20 / 20

Who is the Author of the Postgres 14 Internals book?

Paul Sammy

Sam Altman

Dan Brown

Egor Rogov

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

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

Apply explicit locks

Issues a rollback after the commit to satisfy repeatable read.

Replace procedural code with declarative one.

2 / 10

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 twice, another transaction modifies this row between these reads issue a rollback.

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.

3 / 10

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

True

False

4 / 10

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

True

False

5 / 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.

6 / 10

Which of the below are valid Isolations Levels?

choose 2

Random Scatter

Read Committed

Rollback Read

Serializable

7 / 10

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

Read Committed

Repeatable Read

Read Uncommitted

Serializable

8 / 10

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

False

True

9 / 10

Which parameters sets the database default isolation level?

transaction_isolation_level

default_isolation_level

active_transaction_isolation

default_transaction_isolation

10 / 10

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

choose 3

Serializable

Read Uncommitted

Repeatable Read

Read Committed

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

Page free space can often become fragmented?

True

False

2 / 10

CLOG Pages are never cached in memory?

False

True

3 / 10

Each page has a layer that usually consists of?

choose 2

flashback block

page header

free space

undo segment

4 / 10

UPDATE can be regarded as which 2 separate operations?

COMMIT

DELETE

INSERT

MERGE

5 / 10

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()

6 / 10

status of a subtransaction is written into CLOG?

True

False

7 / 10

A page along with its tuples is read into the buffer cache with compression transformations to enhance cache efficiency?

True

False

8 / 10

CLOG files are stored in which directory?

PGDATA/pg_clog

PGDATA/clog

PGDATA/pg_xact

PGDATA/pg_commit

9 / 10

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

False

True

10 / 10

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

False

True

Your score is

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