NoSql Tutorial 8 : Document databases

It pair each key with a complex data structure known as a document. Documents can contain many different key-value pairs, or key-array pairs, or even nested documents.
·         A document is a key value collection where the key allows access to its value.
·         Documents are not typically forced to have a schema and therefore are flexible and easy to change.
·         Documents are stored into collections in order to group different kinds of data.
Here is a comparison between the classic relational model and the document model :
Relational model
Document model
Tables
Collections
Rows
Documents
Columns
Key/value pairs
Joins
not available


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