Explanation:
In Notes Release 3 and earlier releases, Notes held deleted data-unencrypted-until
empty space, or white space, was removed during a database compact. In
Release 4, this functionality was changed subtly so that the deleted data
was overwritten with random characters to make it irretrievable. (This
is called overwriting free space.) In Release 5 and in Notes/Domino 6,
you can choose to enable/disable this functionality. Overwriting free space
has an adverse affect on database performance.
In most cases, there's no need to keep overwritten data. There are, however,
a few instances when you may want Notes to continue overwriting deleted
data:
1) Physical access to your servers and your databases may be compromised
allowing an unauthorized user to access them.
2) The databases are not encrypted or the ACL leaves the database open
to attack.
3) Your organization has a security policy that requires this feature.
Default:
This property is turned off upon database creation (i.e. overwrite free
space is enabled).
Recommendation:
Disable overwriting of free space by selecting the 'Don't overwrite free'
space option of the database. Do this for multiple files at once via the
Domino Administrator from the 'Files' tab.
References:
Application
Performance Tuning, Part 1
http://www.ibm.com/developerworks/lotus/library/ls-AppPerfpt1/
Domino Configuration Tuner:
This setting is included in the
DCT
catalog of best practices.