What are the different types of NoSQL databases ? Give some examples

webmaster — Mon, 04 Apr 2022 09:11:49 +0000

A Database, which stores data in a format different from relational databases, hence is known as NoSQL Database.
NoSQL- “not only SQL” which pertains to the fact that either the database can store and manage data using “no SQL” at all.
It can work in a combination that combines the flexibility of the newer method (NoSQL) with the strength of the traditional relational system (SQL).
In NoSQL database, there are four types:

1. Key value NoSQL database
2. Document NoSQL database
3. Column family NoSQL database
4. Graph base NoSQL database

In NoSQL database this is the simplest type.
In this type, the data is stored in the form of key/value pairs.
The value can be a JSON, BLOB (Binary Large Objects), string, etc.
It Stores maintain data as pair consisting of an index key and a value.
The value in a key-value store can be anything: a string, a number, but also an entirely new set of key-value pairs encapsulated in an object.

In this, the values are stored in structured documents like XML or JSON, and it is an extension of the simplicity of Key-Value stores.
In object-oriented software, Document stores make it easy to map Objects.
It does not support relations and allows us to store complex data in document formats (JSON, XML etc.).
There is no relational integrity, and Each document in the document store is independent.
It can be used for all use cases of a KV store database, and also data in each document can be in a different format.

It is developed to store and process very large amounts of data distributed over many machines.
The columns are arranged by column family, and they point to multiple columns.
It becomes high performance on aggregation queries like SUM, COUNT, AVG, MIN, etc.

It is the storage of graph–oriented data structures and is used for specific purposes.
A graph database is any storage system that provides index-free adjacency.
No index lookups are necessary, and every node contains a direct pointer to its adjacent element.
There is no need to define the types of edges and vertices because it usually comes with a flexible data model.

What are the features of Apache HBase ?

Editor — Mon, 12 Jul 2021 19:23:16 +0000

What are the features of Apache HBase

- Linear and modular scalability.
- Strictly consistent reads and writes.
- Automatic and configurable sharding of tables.
- Automatic failover support between RegionServers.

- Convenient base classes for backing Hadoop MapReduce jobs with Apache HBase tables.
- Easy to use Java API for client access.
- Block cache and Bloom Filters for real-time queries.
- Query predicate push down via server side Filters.
- Thrift gateway and an REST-ful Web service that supports XML, Protobuf, and binary data encoding options.

How to use Apache HBase REST Interface

Extensible JRuby-based (JIRB) shell.
Support for exporting metrics via the Hadoop metrics subsystem to files or Ganglia; or via JMX.