WEBVTT

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In this lecture, we will get
introduced to DynamoDB in AWS.

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If you're already
familiar with DynamoDb,

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feel free to skip this lecture
and go to the next one.

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DynamoDB is a no SQL database
solution provided by AWS.

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It is a highly scalable database
that can cope with millions

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of requests from applications
such as mobile and web,

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gaming, and IoT.

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It is a fully managed
service from AWS.

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There are no servers that
the users have to manage,

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and this means that AWS
offloads operational tasks

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such as database upgrades,
software installation,

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and patching from the users.

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Along with high scalability, it
also provides low latency data access,

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making it a very popular choice

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for some of the world's
largest scale applications.

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DynamoDb also guarantees high
availability as the data

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is replicated across
multiple AWS regions.

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Dynamodb is a no SQL database.

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This means that it stores data
in the form of key-value pairs

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and documents.

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For example, let's assume that
we want to create a database

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storing information about cars.

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With a key-value database,
this can be done like this.

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The data here is
stored as a table,

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which is a collection
of key-value pairs,

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where a key serves as
a unique identifier.

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Here, we have two
keys called manufacturer

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and the model of the car.

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This can be expanded further to
add more information about

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the car and to make each one
more uniquely identifiable.

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Now let's add two more keys,

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the year and the vehicle
identification number

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or the VIN to the collection.

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Each entry in this
database is called an item,

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and in this example, we have a
database of cars with four items

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at this moment.

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Each item in the database
is composed of one or more attributes.

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The attributes are the keys that
we have defined for the table,

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such as manufacturer,
model, year, and VIN,

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all of which provide meaningful
information about the items.

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Each item in this database can
also be represented like this.

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In order to uniquely distinguish
an item with every other item

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in the table, DynamoDB
uses a primary key.

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For example, the attribute called VIN

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or the vehicle identification
number is a unique value,

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and this can be used to
identify any car in this table.

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A VIN in this case can
be used as a primary key.

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When adding more items, it's
mandatory to define a value

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for the primary key.

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The other attributes
are optional,

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and you can also
have a null value.

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For example, let's add
a fifth item to this table

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with just the vehicle
identification number

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and the manufacturer name,

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which is optional, and let's
not choose to add values

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for any other attributes such
as the model or the year.

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This fifth item is also a
valid entry in this database.