Microsoft Sharepoint Products and Technologies Resource Kit eBook

598 Part VII: Information Management in SharePoint Products and Technologies
Because all content is crawled during a full update, it is the most time-consuming
and resource-intensive of the update types. During a full update, the processor time is
at 100 percent. Full updates should be used less often than other types of updates;
however, there are some circumstances when a full update is needed. Table 21-3 lists
when a full update is needed and why.
Table 21-3 Update Types in SharePoint Portal Server 2003
Circumstance Reason Update Is Needed
Update rules for content
sources are changed
A noise word file is
changed
Incremental Update
An incremental update of a content source crawls and updates only modified and
new content. In an incremental update, SharePoint Portal Server does not index
unchanged content. For this reason, performing an incremental update is faster than
performing a full update.
A periodic incremental update captures changes to the content source. Perform
incremental updates to keep pace with content changes without using the resources
needed for a full update. In general, incremental updates should be used unless
there is a reason for performing a full update, such as reducing the amount of content
that is crawled.
Reducing Index Size by Excluding Links
Update rules control what content is included in the content
index. If a new rule is created that affects only one content
source, a full update is needed only on that one content
source.
A noise word file contains words that are excluded from an
index. If a word is added to the noise file the index must be
updated to remove the word. If a word is removed from the
noise file the word must be added to the index.
A content index is reset Resetting an index removes all information from it. The index
then needs to be completely rebuilt with a full update.
The search server has a
power failure
When a file type is
added or removed
If files are renamed in
the content source
A power failure can cause disruptions in the crawling process.
If documents seem to be missing from the index, a full update
is needed.
The only method to update the index is to perform a full index
update on the affected content sources.
An incremental or adaptive update does not reflect file name
changes in the index. Only a full index update will accomplish
this task.
If you change settings to reduce the amount of content that is crawled (for example,
you exclude links to content that was previously crawled or you reduce the crawling
depth for the content source), the changes will not be reflected with an incremental