Hello and Happy New Year 2012 !!
There is a new blog post, on the Exchange Team Blog, written by Ross Smith IV that refers how the Database Maintenance is done in Exchange Server 2010.
Over the last several months there has been significant chatter around what is background database maintenance and why is it important for Exchange 2010 databases. Hopefully this article will answer these questions.
The following tasks need to be routinely performed against Exchange databases:
The primary purpose of database compaction is to free up unused space within the database file (however, it should be noted that this does not return that unused space to the file system). The intention is to free up pages in the database by compacting records onto the fewest number of pages possible, thus reducing the amount of I/O necessary. The ESE database engine does this by taking the database metadata, which is the information within the database that describes tables in the database, and for each table, visiting each page in the table, and attempting to move records onto logically ordered pages.
You can read the full article at :
Database Maintenance in Exchange 2010 - Exchange Team Blog - Site Home - TechNet Blogshttp://blogs.technet.com/b/exchange/archive/2011/12/14/database-maintenance-in-exchange-2010.aspx