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

What is the process first launched at server start?

pginit

postgres

postman

init

2 / 20

What is the purpose of the template0 database?

No such 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

3 / 20

To understand each other, a client and a server must use one and the same interfacing protocol?

True

False

4 / 20

What is the purpose of wal writer?

executes checkpoints

writes WAL entries to disk

flushes dirty pages to disk.

collects usage statistics for the instance.

5 / 20

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

choose 3

sequences

indexes

triggers

tables

6 / 20

A single Postgres Instance can server only one database?

True

False

7 / 20

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

Schema Path

Directory Path

Search Path

Access Path

8 / 20

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

Sysaux Catalog

Sys Catalog

Sysasm Catalog

System Catalog

9 / 20

The pg_default tablespace should never be used to create user tables?

False

True

10 / 20

System Catalog tables begin with which prefix?

pg_

sys_

cat_

dba_

11 / 20

The default Page size is 2k?

True

False

12 / 20

Each Database has its own System Catalog?

True

False

13 / 20

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

pg_tblspc

pg_tablespace

pg_tabspace

pg_symlinks

14 / 20

Which 3 databases exist directly after cluster initialization?

choose 3 options

template0

postgres

sysaux

template1

15 / 20

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

False

True

16 / 20

pg_catalog schema is used to store system catalog tables?

True

False

17 / 20

What is the default standard size for a fork file?

1GB

1MB

5GB

5MB

18 / 20

Each tablespaces can only be assigned for use by one database

False

True

19 / 20

To be able to restore data consistency, Postgres maintains

undo segments (UNDO)

rollback segments (RBS)

online redo logs (ORL)

write-ahead log (WAL)

20 / 20

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

choose 2

pg_default

pg_global

pg_tablespace

pg_temp

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

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

False

True

2 / 10

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

ACID

SOC2

SAFE

HIPPA

3 / 10

Which of the below are valid Isolations Levels?

choose 2

Read Committed

Random Scatter

Rollback Read

Serializable

4 / 10

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

False

True

5 / 10

Which of the below would best describe a dirty read?

a session being able to see uncommited data altered by another session

reading data direct from memory using pg_dirt

reading the data directly from file using a text editor such as vi or notepad

a session being able to see commited data altered by another session

6 / 10

The SQL standard specifies three isolation levels?

True

False

7 / 10

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.

8 / 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

9 / 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

Issues a rollback after the commit to satisfy repeatable read.

Apply explicit locks

Replace procedural code with declarative one.

10 / 10

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

choose 3

Repeatable Read

Serializable

Read Uncommitted

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

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

False

True

2 / 10

The page header is located in the highest address?

False

True

3 / 10

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

False

True

4 / 10

index row headers like table row headers contain xmin and xmax fields?

False

True

5 / 10

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

xmin

xmas

xmax

xid

6 / 10

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

False

True

7 / 10

Each page has a layer that usually consists of?

choose 2

free space

flashback block

undo segment

page header

8 / 10

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

True

False

9 / 10

Which 2 items does a Virtual XID consist of?

checksum

xmin

backend process ID

sequential number

10 / 10

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

False

True

Your score is

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