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

Files are logically split into pages?

False

True

2 / 20

Which of below are predefined schemas?

choose 2

postgres

pg_catalog

public

system

3 / 20

Which of below are predefined schemas?

choose 3

pg_temp

pg_schema

pg_toast

information_schema

4 / 20

What is the process first launched at server start?

postgres

init

postman

pginit

5 / 20

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

PGCORE

PGTIPS

PGBASE

PGDATA

6 / 20

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

choose 3

indexes

tables

triggers

sequences

7 / 20

Tablespaces can be used to segregate data based on performance needs?

True

False

8 / 20

To be able to restore data consistency, Postgres maintains

rollback segments (RBS)

undo segments (UNDO)

write-ahead log (WAL)

online redo logs (ORL)

9 / 20

How many rows in a page does Postgres aim to have before considering TOAST?

10 / 20

System Catalog tables begin with which prefix?

sys_

pg_

cat_

dba_

11 / 20

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

choose 2

pg_tablespace

pg_default

pg_temp

pg_global

12 / 20

Users should not modify the template0 database

True

False

13 / 20

The information_schema schema provides information on Postgres release notes?

True

False

14 / 20

Postgres by default has built in connection pooling abilities?

True

False

15 / 20

If we create a new tablespace which directory will symbolic links be created from?

pg_tblspc

pg_tabspace

pg_symlinks

pg_tablespace

16 / 20

What column in system catalogs servers as the Primary Key

obj#

oid#

oid

obj

17 / 20

Which fork contains the actual table data?

free space map

table map

visiblilty map

Main fork

18 / 20

What is a schema?

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

Namespace that store all objects of a database

19 / 20

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

True

False

20 / 20

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

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

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

True

False

2 / 10

A phantom read anomaly occurs when?

The same transactions issues a commit, then a rollback to restore data to its original value

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.

A transactions inserts a null value into a not null columns and commits

3 / 10

Which of the below are valid Isolations Levels?

choose 2

Serializable

Rollback Read

Random Scatter

Read Committed

4 / 10

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

choose 3

Repeatable Read

Serializable

Read Committed

Read Uncommitted

5 / 10

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

True

False

6 / 10

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 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.

7 / 10

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

True

False

8 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

9 / 10

The SQL standard specifies three isolation levels?

True

False

10 / 10

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

Read Committed

Serializable

Read Uncommitted

Repeatable Read

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

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

False

True

2 / 10

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

True

False

3 / 10

CLOG files are stored in which directory?

PGDATA/pg_commit

PGDATA/pg_clog

PGDATA/pg_xact

PGDATA/clog

4 / 10

What does an Item Pointer contain?

choose 3

tuple xid

tuple offset from the start of the page

tuple status

tuple length

5 / 10

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

True

False

6 / 10

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

True

False

7 / 10

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

commit log

redo log

transaction log

archive log

8 / 10

The page header is located in the highest address?

False

True

9 / 10

UPDATE can be regarded as which 2 separate operations?

COMMIT

DELETE

MERGE

INSERT

10 / 10

a transaction containing a savepoint is will still be considered as only a single transaction?

False

True

Your score is

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