Selective Access and Editing in a Database

NASA has developed a method and system that provides selective access to different portions of a database by different subgroups of database users. In this system, two or more members of a given access subgroup can simultaneously edit a document accessible to each member. This database system provides selective access to different portions of the database for different groups of users, where the different groups may have overlapping access group memberships. When N users are involved, up to 2N-1 distinguishable access subgroups in a group space can be formed, and no two access subgroups can have the same members. This system is very flexible and allows for change in definition of the portions of the database accessible by a specified access group. Provisions of selective access to the database allow restriction of user access to the information contained in different portions of the database based upon need to know or another suitable authorization scheme.