Indexing Service

Microsoft Indexing Service makes it easier for users to search for data on client computers and servers. Indexing Service scans files on Windows 2000 servers and client computers and builds content and property indexes that dramatically improve search capability and performance. When the service is running, users can search for words and phrases in thousands of files in just a few seconds.

Indexing Service has the following features:

• Searches by content (for example, searches all files containing "revenue projections").
• Searches by document properties (for example, searches all files where AUTHOR contains "Sarah").
• Searches with Boolean operators (for example, AND, OR, NOT).
• Uses a free-text search, which allows users to enter any combination of words without having to learn a particular search syntax.
• Can index volumes on the local computer and also network shares, including NetWare and UNIX servers.
• Provides secure query results.

  Returns only the documents that users are allowed to read. Uses standard Windows 2000 access control lists (ACLs).

• Integrates with NTFS for better performance and reliability.
• Integrates with Internet Information Services (IIS) to provide a search capability for Internet and intranet Web sites.
• Can create customized search forms and user interfaces by using OLE-DB or Microsoft® ActiveX® Data Objects (ADO) scripting.
• Indexes a variety of file formats, including Microsoft® Office 97, Microsoft® Office 2000, text files, and HTML pages.
• Integrates with Windows 2000 user interface and Windows Explorer.
• Provides easy administration by using a Microsoft Management Console snap-in.

When Indexing Service is running on a system, it monitors the server for file modification. When files are modified, they are opened and their contents indexed. Opening files is done by a low priority background process so that general server performance is minimally impacted. In addition, when running on NTFS, Indexing Service uses a number of NTFS advanced features to minimize overall system overhead.

Note

When you first run the service, it must build its indexes from scratch. This involves scanning all the files on the volume. Initial index construction accesses the disk heavily until the indexes have been built. After the indexes have been generated, only incremental updates are needed as files are modified, so further updates are virtually unnoticeable. In all cases, index update is a low priority task and will pause if server resources are needed for other operations.

To search for documents, users just need to select Search for Files and Folders in Windows Explorer or from the Start menu. This brings up a search form allowing users to enter the words for their search. If Indexing Service is running on a file server, users can search network shares efficiently because the search is executed on the server and only the search results are returned across the network.

Integration with Windows 2000 Components

Indexing Service is integrated with many other Windows 2000 components for performance and reliability. The service also uses NTFS features such as bulk ACL processing for much faster security checks before returning search results. It also uses NTFS sparse files to optimize indexes without consuming extra disk space. The service uses the NTFS change log to monitor the volume for file modifications. In this way, the service does not scan the entire volume repeatedly for changes like many other search engines. Instead, when a file is modified, only that particular file is scanned and indexed.

Indexing Service also understands that files can be migrated by Remote Storage. It does not forcibly recall files to index them. It does not rescan if a file has been migrated to secondary storage. This means that even if files have been migrated to tape, users can still search for them. This is ideal if you use Remote Storage to maintain an archival store for documents.

Indexing Service can be switched into a read-only mode. This allows the administrator to back up the indexes. When in read-only mode, the service continues to execute queries but does not update the indexes. The indexes are guaranteed to be consistent and stable so a valid backup can be made. After backing up, you can restore the service to normal operations, and any modifications made to files during the backup are processed normally.

Finally, the full-text indexing engine used by Windows 2000 is compatible with full-text indexing features of Microsoft® SQL Server™ version 7.0. By using the distributed query processor in SQL Server, you can specify queries using structured query language (SQL) and execute them simultaneously against the file system and a database.

Considerations for Using Indexing Service in Your Storage Strategy

Consider the following advantages of using indexing as part of your storage planning:

• Users can easily and quickly find the documents they need on file servers and Web servers.
• Most users do not need to learn a search syntax, although a powerful search language is available for advanced users.
• A single file server and index can satisfy queries for multiple network shares, including files on non-Windows file servers.
• Performance is improved and system load is reduced due to tight integration with the Windows 2000 infrastructure.
• A secure search engine guarantees users cannot find documents that they are not allowed to view or read.
• User interface is easily customized using OLE and ADO programming interfaces.

Consider implementing Indexing Service if any of the following conditions exist in your organization:

• Users cannot find documents on servers or forget the location of documents.
• File servers contain many hundreds or thousands of documents making browsing for particular documents unwieldy or impossible.
• You need to provide search capabilities for a Web site.

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