A document-oriented database stores and manages information as documents rather than as rows in fixed tables. This lesson introduces the document as the central unit of data, explains common document formats, and covers the main operations and ways to find and organize documents.
A document-oriented database, also called a document store, is designed to store, retrieve, and manage semi-structured information. It is a major category of NoSQL database. A document is a self-contained unit that groups related data, much like an object in a programming language.
All flashcards
What is a document-oriented database?
A database designed to store, retrieve, and manage semi-structured information as self-contained documents.
What makes document structure flexible?
Documents in the same collection do not have to share identical fields. Fields may be optional, and documents of the same logical type can differ in composition.
What does CRUD mean?
Create adds a document, Read retrieves documents or fields, Update modifies existing content, and Delete removes documents.
How does a document key help?
A unique key identifies a document so it can be retrieved directly. Many document stores index keys to speed up that retrieval.
How does a document store differ from an opaque key-value store?
A basic key-value store often treats the value as uninterpreted data. A document store can interpret fields and metadata to support content-based queries and updates.
Quiz questions
What is the central unit of data in a document-oriented database?Answer: A self-contained document containing related data.
Which set of actions is summarized by CRUD?Answer: Create, Read, Update, and Delete.
What is the main purpose of a unique document key?Answer: To identify and retrieve a particular document directly.
A query must find phone numbers containing 555 without matching postal codes containing 555. What capability helps a document store distinguish them?Answer: Interpreting document structure and querying specific fields.
A new optional field is added to some documents in a collection. What is generally true in a document store?Answer: Existing documents can retain their previous structure while newer documents include the field.