Review questions

What is the primary key field?

How many filed in the document?

Which filed represented by array?

Which filed represented as embedded document

How many embedded document in the main

document?

For what value, the instruction "skills.

$0$

$$

$"$

$$

$$

is

denudes?

For what value, the instruction "address.street"

is denudes?

$\_$

id: ObjectId

$($

$"$

$32521$

df

$3$

f

$4948$

bd

$2$

f

$54218$

$"$

$)$

$,$

firstName: "John",

lastName: "King",

email:

$"$

john.kingeabc.com",

salary:

$"$

$3$

$$

$$

e

$0$

$"$

$,$

DoB: new Date

$($

$\text{'}$

Mar

$24$

$,$

$$

$2011$

$\text{'}$

$)$

$,$

skills:

$[$

$"$

Angular

$"$

$,$

$$

$$

$"$

React

$"$

$,$

$"$MongoDB$"$

$]$

$,$

address: :

street: "Upper Street",

house:

$"$

No

$1$

$"$

$,$

city: "New York",

country: "USA"

$\}$

$\}.$ What are document databases good for?

Give examples of a document database?

How do document databases work?

How are documents stored in a database?

Which field is always the first field in a document?

Why is array used in documents

Mention two disadvantages of document databases. In NoSQL, what is the term Flexible schema is mean?