WinFS - WikiHQ

WinFS (short for Windows Future Storage) was the code name for a canceled data storage and management system project based on relational databases, developed by Microsoft and first demonstrated in 2003. It was intended as an advanced storage subsystem for the Microsoft Windows operating system, designed for persistence and management of structured, semi-structured and unstructured data.

WinFS includes a relational database for storage of information, and allows any type of information to be stored in it, provided there is a well defined schema for the type. Individual data items could then be related together by relationships, which are either inferred by the system based on certain attributes or explicitly stated by the user. As the data has a well defined schema, any application can reuse the data; and using the relationships, related data can be effectively organized as well as retrieved. Because the system knows the structure and intent of the information, it can be used to make complex queries that enable advanced searching through the data and aggregating various data items by exploiting the relationships between them.

While WinFS and its shared type schema make it possible for an application to recognize the different data types, the application still has to be coded to render the different data types. Consequently, it would not allow development of a single application that can view or edit all data types; rather, WinFS enables applications to understand the structure of all data and extract the information that they can use further. When WinFS was introduced at the 2003 Professional Developers Conference, Microsoft also released a video presentation, named IWish, showing mockup interfaces that showed how applications would expose interfaces that take advantage of a unified type system. The concepts shown in the video ranged from applications using the relationships of items to dynamically offer filtering options to applications grouping multiple related data types and rendering them in a unified presentation.

WinFS was billed as one of the pillars of the "Longhorn" wave of technologies, and would ship as part of the next version of Windows. It was subsequently decided that WinFS would ship after the release of Windows Vista, but those plans were shelved in June 2006, with some of its component technologies being integrated into ADO.NET and Microsoft SQL Server.

Motivation

Many filesystems found on common operating systems, including the NTFS filesystem which is used in modern versions of Microsoft Windows, store files and other objects only as a stream of bytes, and have little or no information about the data stored in the files. Such file systems also provide only a single way of organizing the files, namely via directories and file names.

Because a file system has no knowledge about the data it stores, Using common file formats is a workaround to this problem but not a universal solution; there is no guarantee that all applications will use the format. Data with standardized schema, such as XML documents and relational data fare better, as they have a standardized structure and run-time requirements.

Also, a traditional file system can retrieve and search data based only on the filename, because the only knowledge it has about the data is the name of the files that store the data. Different data types expose different properties. Besides that, WinFS also allows different data instances to be related together; such as a document and a contact can be related by an Authored By relationship. Thus WinFS can reduce redundancies.

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| bar5-text=Outlook <span title="Local Information Store">LIS</span> but the Cairo project was shelved, and with it OFS. However, later during the development of COM, a storage system, called Storage+, based on then-upcoming SQL Server 8.0, was planned, which was slated to offer similar aggregation features. and build 4051 of Windows Vista, then called by its codename "Longhorn", given to developers at the Microsoft Professional Developers Conference in 2003, included WinFS, but it suffered from significant performance issues. The beta was refreshed on December 1, 2005 to be compatible with version 2.0 of the .NET Framework. WinFS Beta 2 was planned for some time later in 2006, and was supposed to include integration with Windows Desktop Search, so that search results include results from both regular files and WinFS stores, as well as allow access of WinFS data using ADO.NET.

On June 23, 2006, the WinFS team at Microsoft announced that WinFS would no longer be delivered as a separate product, and some components would be brought under the umbrella of other technologies. Many of the principle features Microsoft intended to provide with WinFS included a pane for metadata property editing, breadcrumb-based property navigation, filtering or stacking items over properties, incremental search, and saved searches; these features were incorporated in Windows Vista. Query composition, a feature of WinFS that allowed users to perform additional searches that reuse the results of a previous query,

Examples of uses of the technology are the object-relational mapping components into ADO.NET Entity Framework; support for unstructured data, adminless mode of operation, support for file system objects via the <code>FILESTREAM</code> data type, and hierarchical data in SQL Server 2008, then codenamed Katmai, as well as integration with Win32 APIs and Windows Shell and support for traversal of hierarchies by traversing relationships into later releases of Microsoft SQL Server;

Data storage

Architecture

thumb|Architecture of the WinFS Stack

WinFS uses a relational engine, which derives from SQL Server 2005, to provide the data-relations mechanism. WinFS stores are simply SQL Server database (.MDF) files with the FILESTREAM attribute set. These files are stored in the access-restricted folder named "System Volume Information" (placed in the volume root), in folders under the folder "WinFS" with names of GUIDs of these stores.

WinFS.exe, which hosts the relational datastore
WinFSSearch.exe, which hosts the indexing and querying engine
WinFPM.exe (WinFS File Promotion Manager), which interfaces with the underlying file-system

It allows programmatic access to its features via a set of .NET Framework APIs. These enable applications to define custom-made data types, define relationships among data, store and retrieve information, and allow advanced searches. Relations can also be specified by other applications or the user.

WinFS provides unified storage, but stops short of defining the format that is to be stored in the data stores. Instead it supports writing data in application-specific formats. But applications must provide a schema that defines how the file format should be interpreted. The Contact Item defined in this way will be used to store information regarding the Contact, by populating the properties field and storing it. Only those fields marked as mandatory needs to be filled up during initial save. which are executed when a certain condition is met. WinFS rules work on data and data relationships. For example, a rule can be created that states that whenever an Item is created which contains field "Name" and if the value of that field is some particular name, a relationship should be created that relates the Item with some other Item. WinFS rules can also access any external application. For example, a rule can be built which launches a Notify application whenever a mail is received from a particular contact. The data in them can be accessed by accessing the properties of individual objects. A set of all matches is returned, which can then be bound to a UI widget for displaying en masse or enumerating individually. A WinFS item can also be copied to a non-WinFS file system, but unless that data item is put back into the WinFS store, it will not support the advanced services provided by WinFS.

The WinFS API also provides some support for sharing with non-WinFS applications. WinFS exposes a shell object to access WinFS stores. This object maps WinFS items to a virtual folder hierarchy, and can be accessed by any application. which allowed one to browse WinFS stores by presenting a hierarchical view of WinFS Items. It automatically generated virtual folders based on access permissions, date and other metadata, and presented them in a hierarchical tree view, akin to what traditional folders are presented in. The application generated tabs for different Item types. StoreSpy allowed viewing Items, Relationships, MultiSet, Nested Elements, Extensions and other types in the store along with its full metadata. It also presented a search interface to perform manual searches, and save them as virtual folders. The application also presented a graphical view of WinFS Rules. However, it did not allow editing of Items or their properties, though it was slated for inclusion in a future release. But the WinFS project was cut back before it could materialize.

Type Browser

WinFS also includes another application, named WinFS Type Browser, which can be used to browse the WinFS types, as well as visualize the hierarchical relationship between WinFS types. A WinFS type, both built-in types as well as custom schemas, can be visualized along with all the properties and methods that it supports. It also shows the types that it derives from as well as other types that extend the type schema. However, while it was included with WinFS, it was released as an unsupported tool. It presents a graphical interface for writing Opath queries. It can be used by selecting target object type and specifying the parameters of the query. It also includes Intellisense-like parameter completion feature. It can then be used to perform visualization tasks like binding results of a query to a DataGrid control, create views of the data in WinFS itself, or just extract the query string.

Project "Orange"

Microsoft launched a project to build a data visualization application for WinFS. It was codenamed "Project Orange" and was supposedly built using Windows Presentation Foundation. It was supposed to provide exploration of Items stored in WinFS stores, and data relationships were supposed to be a prominent part of the navigation model. It was supposed to let people allow organization of the WinFS stores graphically as well – productizing many of the concepts shown in the IWish Concept Video WMV File. However, since the WinFS project went dark, the status of this project is unknown.

References

External links

WinFS Blog
WinFS at the Microsoft Developer Network (Internet Archive cache)
Channel 9 Videos
WinFS Newsgroup
WinFS Beta 1 Preview (Internet Archive cache)
WinFS area on NetFXGuide.com (Internet Archive cache)