What is NoSQL?
A NoSQL database provides a mechanism for storage and retrieval of data which is modeled in means other than
the tabular relations used in relational databases. The data structures used by NoSQL databases (e.g.
key-value, wide column, graph, or document) are different from those used by
default in relational databases, making some operations faster in NoSQL. NoSQL
databases are increasingly used in big data and real-time web applications.
NoSQL (Not Only SQL):
• Databases
that “move beyond” relational data
models. It does not have no tables, limited or no use of SQL.
ü Focus
on retrieval of data and appending new data. But not necessarily tables.
ü Focus
on key-value data stores that can be used to locate data objects.
ü Focus
on supporting storage of large quantities of unstructured data .
ü SQL
is not used for storage or retrieval of data.
ü No
ACID (atomicity, consistency, isolation, durability).
• NoSQL
focuses on a schema-less architecture
(i.e., the data structure is not predefined)
• In
contrast, traditional relation DBs
require the schema to be defined before the database is built and populated.
ü Data
are structured
ü Limited
in scope
ü Designed
around ACID principles.
