ravendb-example

A sample ASP.NET 5 application using RavenDB

Some highlighted features of RavenDB 3

• New Raven Studio! No more Silverlight!!!
• Support for Voron storage engine (port of Lightning Memory-mapped Database)
  • More performant
  • No DTC transaction support
• Some changes to index performance
• WhatChanged and HasChanges available on session
• Missing properties on save operation are retained in database
• Full details in links at the bottom

Advantages of a document database over RDBMS

• Ease of development
  • No difference between data storage model and application model
  • Schemaless, so the document structure is created on the fly
  • Easier to change document structure in a rapid development workflow
• Can be more efficient if used properly
  • Documents usually stored as continguous memory blocks
  • Better for distributed database system because better locality can be maintained

Some thoughts on document database design

Traditional RDBMS

• Domain objects spread across many tables

• Normalization

• Lots of foreign key relationships to produce complete picture

  // Orders
  {
    "Id": "1",
    "UserId": "1"
  }
  
  // OrderLines
  {
    "Id": "1",
    "ProductId": "1",
    "Quantity": "10",
    "Price": "10.00"
  }
  
  // Products
  {
    "Id": "1",
    "Description": "Blah blah blah",
    "Price": "10:00"
  }
  

Document Databases

• Domain objects consolidated into fewer documents
• Denormalization
• Less foreign key relationships

  // Orders
  {
    "Id": "1",
    "UserId": "1",
    "OrderLines":
    [
      {
        "Id": "1",
        "ProductId": "1",
        "Quantity": "10",
        "Price": "10.00"
      }
    ]
  }
  
  // Products
  {
    "Id": "1",
    "Description": "Blah blah blah",
    "Price": "10:00"
  }

How to think about it

• Focus less on how the data is stored, and more on how it will be accessed
• Ask yourself, will this type ever need to be accessed independently, or does it only make sense within the context of some parent document?

Indexes

• Queries are always against indexes
• Indexes are built asynronously in the background
• Data can be stale
• Static/Dynamic indexes
• ACID/BASE - http://ravendb.net/docs/article-page/2.5/csharp/client-api/advanced/transaction-support

Examples of usage in this app

• This is a simple application to demonstrate basic database creation, session usage, and CRUD operations
• Start with DocumentStoreLifecycle to see how to create a database
• See the PeopleController for basic usage of Raven, including:
  • Creating
  • Editing
  • Deleting
  • Loading
  • Loading multiple docs
  • Querying with Linq
  • Some advanced querying features
  • Paging
  • Stale data

Links

• Document design
  • http://ravendb.net/docs/article-page/2.5/csharp/theory/document-structure-design
  • http://ayende.com/blog/4466/that-no-sql-thing-modeling-documents-in-a-document-database
  • http://docs.mongodb.org/manual/core/data-modeling-introduction/
• More on ACID/BASE nature of Raven
  • http://ayende.com/blog/164066/ravendb-acid-base
• Server configuration
  • http://ravendb.net/docs/article-page/3.0/csharp/server/configuration/configuration-options
• New in RavenDB 3
  • http://ravendb.net/docs/article-page/3.0/Csharp/start/whats-new