Document stores provide a native database management system for semi-structured data. Document stores also scale to Gigabytes or Ter- abytes of data, and typically millions or billions of records (a record being a JSON object or an XML document).
Introduction to Document Stores
a document store, unlike a data lake, manages the data directly and the users do not see the physical layout.
Unlike data lakes, using document stores prevent us from breaking data independence and reading the data file directly: it offers an automatic manager service for semi-structured data that we need to throw and read quickly.
In this case, we would like an efficient manner to store documents, as original relational databases did, while offering a relaxed version of the integrity properties.
Size of the documents
a collection can have millions or billions of documents, while each single document weighs no more than 16 MB
This is why document stores can scale up to Gigabytes or terabytes of data.
MongoDB
MongoDB is one of the most famous document storage engines.
Storage
Documents in MongoDB are usually stored in BSON format, an equivalent method to JSON (see HTML e Markup) but in binary format as it is usually more efficient.
Operations
Similarly to HTML APIs, MongoDB offers CRUD operations. It is important to know the syntax of these operations.