Best Document Databases

Document databases are a class of non-relational databases (NoSQL databases). Document databases store related data in a document format. They are used to design, query, and store the data in a document format (JSON document, XML, YAML, or binary formats such as BSON and PDF). The software is used for storing, retrieving, and managing document-oriented information also known as semi-structured data. Document databases software, also known as document-oriented databases software, is a subclass of key-value stores, which is a NoSQL database concept. In a key-value store or key-value database, data is managed (stored, received) by using associative arrays. This type of data structure is called a “dictionary”. Dictionaries are a collection of objects, and objects are the central data storage repository that store different fields that contain the data. Some of the key examples include MongoDB, Amazon DynamoDB, Google Cloud Firestore, Couchbase Server, Apache CouchDB, among several others. Many of these databases such as MongoDB and Couchbase server are open source in nature.

To call the data when required, a key is used, which acts as the unique identifier for the record within the entire database. When talking about document databases, it’s important to identify what exactly is a “document”. A document stores or encodes all the data in a standard format. These formats include JSON, XML, YAML, and others. 

Document databases differ greatly from traditional relational SQL databases. The major cause of difference between the two types of databases is that relational databases store data models as a relation—tables, rows, and an object could be a part of numerous tables. However, document databases store all the related information of an object within a single instance of the database, and each object can be stored uniquely. Document databases do not have any restrictions as relational databases do.

CRUD operation

The core operations for document databases are abbreviated as CRUD—create, retrieve, update, and delete. These are the four basic operations that all document databases support.

What is a key?

As stated earlier, a key acts as a unique identifier that is representative of the document. It is used to retrieve the data from the document database. There is usually an index of keys available, which makes it easier for the user to refer to and call back the data represented by that particular key. In case a user needs to add or delete a document within the document database, a key can be used for the same.

Data retrieval 

Although a key-to-document method is enough for data retrieval, the document database offers an API that users can use to query data based on content. The set of query language or query APIs vary significantly between different data model implementations. In this, document databases make use of the metadata of the content to classify the content and differentiate it from one another.

Data organization

There are several ways to arrange documents within document databases software. A document can exist as single or multiple collections.

Hierarchy: Documents are grouped in a tree-like structure and have a typical path.

Collections: Group of documents within the software. 

Data tags: Documents or additional data located outside the content.

Why use document databases?

Since the data is stored in a format that is very close to the application development code used by developers, there is much less translation required for the data to be used by an application. These types of databases give developers the freedom and the flexibility to rework various documents in the format suited for that application. In turn, their application needs to change over time, the document database can also be modeled in the same data format as required by the application.

When can a user opt for document databases?

Document databases software is used to store large volumes of data in a key-value, making it easy for the user to access the data. Considering the significant amount of data to be processed, some of the key uses of the software include content management, user profiles for a company, catalogs, and several other documents.

The need for document databases has become imminent with the rise of unstructured data. The following section covers the core features of document databases software that can help users in several ways:

Document databases software are NoSQL: NoSQL database software was created to meet the needs of the internet era, with the rise of unstructured data. NoSQL document databases have been attributed with increasing the pace of app development and supporting data scaling and new application structures and paradigms. Since document databases are NoSQL in nature, several elements can be indexed and called faster by application developers. The data structure in this software is designed for unstructured data or big data, allowing it to plow through large amounts of data while being able to maintain its efficiency and flexibility. 

Schema support: Document databases software can support several different schemas of data because there are no restrictions in the structure of the data. The schema is flexible and can be used for different types of document formats to process queries faster.

Richness of indexing: Several document databases support ad hoc queries, indexing, full-text search, and real-time data collections to ensure that users can access, analyze, and transform data as required. 

Distributed database: Document databases software are distributed as their central principle, unlike monolithic relational databases. Since the documents are individual and independent, they can be located or distributed on multiple servers across the globe. This is very useful for companies such as e-commerce that have locations across the globe. It also supports replication and self-healing capabilities to ensure that all applications support high availability. The software also supports data sharding (a data partitioning technique) to ensure scalability across numerous independent servers.

The inclusion of document databases software within a firm can help manage thousands of documents that exist within a company. Some of the key benefits of document database software include:

Easy availability: The data is not spread out or linked over different databases but rather is available in a single database. This is one of the main benefits of document databases. Although interlinking of documents is possible, it is not usually recommended since it would make the database relational in nature and also add to the complexity of managing the database. 

No foreign keys: Having no foreign keys indicates that there is no relationship formed between the data. Without the existence of this dynamic, documents can be created, managed, and deleted independently making it much faster to process data for several applications querying it.

Open formats: One of the key benefits of using document databases is that they support several open formats. The process can use XML, JSON, and several other formats for the data.

Supports scalability: As the amount of data generated increases every minute, the database software being used by customers also needs to ensure flexibility and scalability. Document databases allow users to easily add datasets to scale up, which means more future-proof features.

New integration support: Since document databases are much more flexible and scalable compared to traditional relational databases, integrating new data into the database software is easy. There is no need for consistency in data formats, and large amounts of unstructured data or big data can be stored.

Fast query nature: One of the key features of document databases software is its nature to improve the speed of queries. Using document databases can enable several app developers to store and query requested data in the same document-model format that is being used in the code being developed. For example, in the healthcare field where time is of the essence, a user can immediately get access to health records instead of facing any delays or issues.