Full-Text Indexing | MCSA[s]MCSE

Any client can search the Exchange databases for information by default. However, Exchange Server 2003 also provides a feature called full-text indexing , in which every word in a store (including those in attachments) is indexed for much faster search results.

Some of the key benefits provided by full-text indexing include:

Indexing is configured on a store-by-store basis, allowing you control which stores get indexed and which do not. As well, you can individually configure how often the index is updated and where the index is to be kept for each store configured for indexing.
Searches are faster because they are performed against a prepopulated index instead of the raw database itself.
Searching is done for related words as well, increasing the chance of locating the desired information.

Searching of many common document types is provided for those documents contained in the store, such as e-mail attachments and documents located within a public folder. The following file formats are indexed: ASP, DOC, EML, HTM, HTML, PPT, TXT, and XLS.

While full-text indexing does provide significant advantages, there are a few considerations you must make before you decide to use it:

Building and updating the index consumes server resources. For large stores, the CPU usage and time involved in creating the index can be considerable.
An indexed store requires about 20 percent more disk space than a nonindexed store.
During the time that a store is being indexed or updated, clients may receive incomplete search results. Also, in general, search results are accurate only up to the time the store was last indexed.

Creating a Full-Text Index

Exercise 9.3 outlines the steps for creating a full-text index for a mailbox store.

EXERCISE 9.3: Creating a Full-Text Index for a Mailbox Store

Click Start > Programs > Microsoft Exchange, and then select System Manager.
Expand the organization object, the Administrative Groups folder, the specific administrative group, the server, and the storage group that contains the store you want to index.
Right-click the store and select the Create Full-Text Index command from the context menu.
In the dialog that opens, either type a path for the location of the index catalog or accept the default location, and then click OK.

Configuring Properties for a Full-Text Index

Once the full-text index is created (and this can take some time, depending on the size of the store being indexed), you can configure indexing properties by opening the property pages for the store and switching to the Full-Text Indexing page, shown in Figure 9.10. This page holds two parameters you can configure:

The Update Interval option is used to schedule the interval at which changes in the store are added to the index.
The This Index Is Currently Available For Searching By Clients option opens the index for searching. It is recommended that you disable this during the initial creation of the index and also during complete rebuilds of the index. This helps prevent incomplete searches being returned to clients who perform searches while the index is being built.

Figure 9.10: Viewing full-text indexing information for a store

Managing a Full-Text Index

When you right-click a store for which full-text indexing has been enabled, several management tasks are available to you on the context menu that opens. These tasks include the following:

Start Incremental Population, which finds any changed information in the store and adds it to the index.
Start Full Population, which rebuilds the entire index. During this process, Exchange purges the index one document at a time instead of purging the entire index and then rebuilding it. This helps speed up the rebuilding process.
Pause Population, which stops any population process that is currently happening without causing any loss of indexing.
Stop Population, which halts any population process that is currently happening and causes any updates to be lost.
Delete Full-Text Index, which deletes the index catalog associated with the store.

Troubleshooting Full-Text Indexing

Two tools will be helpful to you in troubleshooting problems with full-text indexing: Gather files and Application Logs.

Gather files Gather files are created whenever a full-text index is built and contain a record of errors encountered during indexing. These files are located in the \ProgramFiles\Exchsrvr\ExchangeServer\GatherLogs folder by default and have the extension .gthr . These files identify all documents that were not successfully indexed. For the exam, it ‚ s really only important that you know what these files are and where to find them. You can learn more about using them from the Exchange documentation.

Application Log If indexing cannot be performed on an item or is stopped altogether for some reason, a search error is logged in the Windows Application Log. If the service is experiencing problems, you can also find errors relating to the Microsoft Search Service itself.