NOSQL databases provide flexible, scalable alternatives to traditional relational databases. The main types of NOSQL databases are document stores, key-value stores, column family stores, and graph databases. Each has different data models and capabilities such as horizontal scaling, limited transactions, and using relationships as an index.

1. NOSQL OVERVIEW

2. NOSQL DATABASES
• A cheeky acronym for Not Only SQL
• More confrontationally, No to SQL.

3. THE RISE OF NOSQL
DATABASES

4. TYPES OF NOSQL DATABASES

5. DOCUMENT STORES
• Reply on indexes to facilitate access
to documents based on their
attributes.

6. DOCUMENT STORES
• Data model of a document store is one
of disconnected entities
• Should scale horizontally, as there’s no
contended state between mutually
independent records at write time
• Limitation:Transactions are limited to the
level of an individual record.
• Support for operating across sets of
documents atomically is emerging

7. KEYVALUE STORES
• Large, distributed hash map data
structures that store and retrieve
opaque values by key
• Level of insight offered into data is due
to data opacity.
• To retrieve insight across individual
records, a cluster computing framework
like Map reduce or spark is used.

8. KEY-VALUE STORES
1.Key = Domain specific identifier
2.Key is hashed with a uniform distribution
hash function.
3.Hashed key is used to store values in a
corresponding bucket.
4.A similar procedure is used to retrieve
data.
5.For fault tolerance each bucket is
replicated onto several machines.

9. COLUMN FAMILY
• Modelled on Google’s
BigTable.
• Logically speaking, it’s just a
map of maps.

10. COLUMN FAMILY
• Simplest storage unit:
Column consisting of name
value pair.
• Super column: Sorted set of
columns with a name.

11. COLUMN FAMILY
• Columns are stored in rows, and when a row contains
columns only, it is known as a column family.
• When a row contains super columns, it is known as a
super column family.

12. COLUMN FAMILY
• In a column family database, each row in the table represents a
particular overarching entity. They are containers for related
pieces of data.

13. COLUMN FAMILY
• Where each row gives
a complete view of one
entity, the column view
naturally indexes
particular aspects across
the whole dataset.

14. GRAPH DATABASES
• It contains nodes and relationships.
• Nodes contain properties (key-
value pairs).
• Nodes can be labeled with one or
more labels.
• Relationships are named and
directed, and always have a start
and end node.
• Relationships can also contain
properties.

15. GRAPH DATABASES
• Don’t depend heavily on
indexes because the graph itself
provides a natural adjacency
index
• Relationships attached to a
node naturally provide a direct
connection to other related
nodes of interest.
• Graph queries use this locality
to traverse through the graph
by chasing pointers.