System and Global Databases

The Hub is the location where the overall project administration takes place. It is the only location where the user can create and modify:

• Teams

• Databases (except for working extracts, which can be created at Satellites)

• Roles (if using Data Access Control (DAC))

• Other Locations and Location Groups

  Global projects are set up just like standard projects, by creating the project directory and its sub-directories, and setting environment variables in the normal way. At this point, the standard System database stores references to all the Admin elements (Teams, Users, Databases (DBs), Multiple Databases (MDBs) etc.) in the project.

  Then give the command to make the project Global.

  Note:
  The location at which the user makes the project Global becomes the Hub: this location can be changed later. Making the project Global splits the standard System database into a new Global database, which stores information about Teams, Databases, Locations and Roles, and a new System database which continues to store information about all the other Admin elements:

• The Global database is propagated to the Satellite locations, but it can only be modified at the Hub.

• Each location, including the Hub, also has its own System database. Each System database is propagated to all locations automatically, even if the System database is administered locally. A Satellite System database can be modified by an Administrator who is at the primary location for that database. The primary location can be the Satellite itself, or it can be a remote location, such as another Satellite or the Hub. If the primary location is remote (not at the Satellite itself) an Administrator at the Satellite cannot modify the Satellite’s System database. The Hub System database, like the Global database, can only be modified at the Hub.

  Note:
  The local system database filename is of the form prjsys, where prj is the project code. There will also be a file of the form prjsys_loc for other locations: this is for use in centralised administration (i.e. where one location administers all of the other satellites remotely.).

• Once a project has been converted to a Global project, it cannot be converted back to a standard project. In effect, a single-location Global project will behave like a standard project, as far as most base product users are concerned. However, the user can use the REPLICATE SYSTEM STANDALONE command to replicate the project structure for a Global project as for a standard (non-Global) project.

As explained above, if necessary, the System Administrator at the Hub or at a Satellite can change a Satellite System database remotely, provided that the Administrator is at the primary location for that database. However, any location can Query System database data (about Users, MDBs and so on) at any other location.

When you make a project Global, a transaction database is also created, to store details about the progress of issued commands. Global provides a facility so that the user can monitor the progress of Global commands, and, if necessary, cancel commands that have not been carried out yet. Refer to Monitoring Command Progress for further information.