nosql- introduction for beginners

NO-SQLIt’s not

Not Only SQL

It’s

What is NOSQL?

•Early ages, Relational databases allowed applications to

store data through a standard data modeling and query

language SQL.

•Expensive and data schemas were fairly simple and

straightforward. Since the rise of the web, the volume of

data stored about users, objects, products and events has

exploded.

•Data is also accessed more frequently, and is processed

more intensively

•Low-cost, commodity cloud hardware has emerged to

replace vertical scaling on highly complex and expensive

single-server deployments.

•Engineers now use agile development methods, which aim

for continuous deployment and short development cycles,

to allow for quick response to user demand for features.

What was the need?

What urged to introduce NOSQL?

•Trend 1: BigUsers

•Trend 2: Size(BigData)

•Trend 3: Connectedness(InterConnected

Data)

•Trend 4: Semi-structure(Complex Data

Structure)

•Trend 5: Architecture

Trend 1: BigUsers

161

253

397

623

988

0

200

400

600

800

1000

1200

2006 2007 2008 2009 2010

data(in exabyte)

Trend 2: Size(BigData)ExaBytes of data stored per year

Source: neotechnology

Trend 3: Connectedness

• To handle hierarchical nested data structures

SQL, you would need multiple relational tables

with all kinds of keys.

• there is a relationship between performance

and data complexity. Performance can degrade

in a traditional RDBMS as we store the massive

amounts of data required in social networking

applications and the semantic web.

• Individualization of content

Trend 4: Semi-structure(Complex

Data Structure)

Trend 4: Semi-structure(Complex

Data Structure)

Source:couchbase.com

Trend 5:

Architecture

Why is so

NoSqlin

spotlight

?

1. Scaling.

•The process of adding

more capacity means

taking existing actors in a

system and increasing

their individual power.

•A single server has to

host the entire database

to ensure reliability and

continuous availability of

data. This gets expensive

quickly, places limits on

scale.

Vertical Scaling(Relational):

Example, let’s assume you have 3 trucks that can carry 25 felled trees per load, and it takes 1 hour to move each load down the road, our maximum

capacity will be:

3 trucks * 25 trees * 1 hour/load = 75 trees processed per hour

Assuming we’ve chosen a vertical scaling capacity model, what if we

wanted to process 150 felled trees?

We’d need to do one of two things:

1. either double the carrying capacity of each truck (50 trees per hour),

2. halve the time it takes for each truck to process each load (30 minutes).

3 trucks * 50 trees * 1 hour/load = 150 trees processed per hour

OR

3 trucks * 25 trees * 30 minutes/load = 150 trees processed per hour

We haven’t increased the number of actors in the system, but we have

increased the productivity of each actor to achieve the desired jump in

capacity.

Vertical Scaling(Relational):

Horizontal Scaling(NoSql):•Instead of increasing

the capacity of each

individual actor in the

system, we simply add

more actors to the

system.

•By adding servers

instead of

concentrating more

capacity in a single

server.

Horizontal Scaling(NoSql):

In our lumber harvesting example, this means adding more

trucks to move the lumber. So when we need to increase

our capacity from 75 trees per hour to 150 trees per hour, we

simply add 3 more trucks:

6 trucks * 25 trees * 1 hour/load = 150 trees processed per

hour

The productivity of each actor in the system remains the

same, but we’ve added more trucks to the system.

2. Dynamic Schemas.

Dynamic Schemas:

•Relational databases require that schemas

be defined before you can add data.

•This fits poorly with agile development

approaches, because each time you

complete new features, the schema of your

database often needs to change.

•If the database is large, this is a very slow

process that involves significant downtime.

How RELATIONAL DATABASE does it??

Dynamic Schemas:

And how NOSQL does:

•NoSQL databases are built to allow the insertion

of data without a predefined schema.

•That makes it easy to make significant

application changes in real-time, without

worrying about service interruptions – which

means development is faster, code integration is

more reliable, and less database administrator

time is needed.

3. Sharding.

Sharding:

How RELATIONAL DATABASE does it??

Sharding is the process of storing data records

across multiple machines.

•As SQL scales vertically, sharding is done by

complex arrangements for making hardware act

as a single server

Sharding:And how NOSQL does:

•NOSQL natively and automatically spread data

across an arbitrary number of servers, without

requiring the application to even be aware of

the composition of the server pool.

• Data and query load are automatically

balanced across servers, and when a server

goes down, it can be quickly and transparently

replaced with no application disruption

(replication).

4. Replication.

Replication:

•NoSQL databases also support data

replication, storing multiple copies of data

across the cluster, and even across data

centers, to ensure high availability and

support disaster recovery.

•A properly managed NoSQL database

system should never need to be taken offline,

for any reason, supporting 24x365 continuous

operation of applications.

5.Integrated Caching.

Integrated Caching:

How RELATIONAL DATABASE does it??

•In relational technology, caching tier is usually

a separate infrastructure tier that must be

developed to, deployed on separate servers,

and explicitly managed by the operating team

•To reduce latency and increase sustained

data throughput, NoSQL database

transparently cache data in system

memory.

•This behavior is transparent to the

application developer and the operations

team

Integrated Caching:

And how NOSQL does: