Important Microsoft Search Technologies

The Microsoft Search (MS Search) team creates technologies that perform three main functions:

• Crawling, the process by which a search engine locates and parses text in different sources, such as file system information, HTML pages, e-mail stores, documents stored on file shares, and databases
• Indexing, in which each word encountered during crawling is arranged in an index, where it’s linked to its occurrences in any of the original sources
• Ranking, the process of displaying a list of search results so that the most relevant sources are displayed first.

Crawling

When first building an index, a search engine performs a full crawl-a fairly slow process in which information is gathered from every source that the user wants included in the results. Subsequently, the engine conducts periodic incremental crawls, in which it updates the index only for documents that have been updated or deleted. More recent Microsoft products, such as SharePoint Portal Server (SPS) and MSN Desktop Search, use adaptive crawling, which identifies material that is more likely to be updated frequently and crawls only those sources likely to have been updated since the last crawl. This is quicker than incremental crawling, which checks the time stamp for every source in the index.