What is Indexing in Exchange Server 2010

Content indexing is a built-in feature which enables fast searches and lookups through mailboxes and public folders stored in the Exchange Server. Exchange Server 2010 supports two types of indexing:-

1. Standard Indexing with Exchange Search

2. Full-text Indexing with Exchange Store Search

Exchange Search is automatically implemented and managed by the Exchange Server storage. Exchange Search is generally used for common fields, such as message subjects, or quickly search To, From and so on. User can take advantage of Find feature in Microsoft Office Outlook for Exchange Search.

As we know users can perform Advanced Search from their Outlook by clicking on Search box (or Ctrl+E), then Search Options and then Advanced Find. Users enter the parameters and send the request for searching the contents. Without Exchange Store search, it searches through every message in the folder which may take a significant time when mailbox and public folders grow. Also, Exchange Server is unable to search through message attachment with Standard Searching.

The main advantage of Exchange Store Search is that Exchange Server builds an index of all searchable text in a mailbox and public folder database before users search. This index can be rebuilt or updated at every predefined interval. Users can also quickly find any text within a document or attachment.

But the limitation of Exchange Store Search is this is a very resource-intensive feature. Creating and maintaining indexes requires a lot of CPU time and memory which can adversely affect Exchange performance. It also consumes disk space. When we create a new index, it uses 10 to 20 percent of the total size of the Exchange database. This space increase when we update an index, but it only stores increment changes.

Each Exchange database has an index. If we make a database copy, index copy is also created and so need to rebuild the new index.