Database Management
Reference Manual
Inter-DB Connection Macros
Access to a DB is usually controlled in such a way that only one user can modify the content of that DB at any one time; that is, only one user can have Write access to the DB. Other users may have simultaneous Read access, depending how access rights have been set up in the ADMIN module.
In a multi-disciplinary project, in which different teams of users work on different aspects of the design, an individual user will usually have Read/Write access to the DBs controlled by their own team and Read-only access to DBs controlled by other teams. This works well until a user needs to connect an item in their team’s DB to an item in another team’s DB; for example, a member of the Piping team may wish to connect a Branch in a Piping DB to a Nozzle in an Equipment DB (to which they have Read-only access). In such a case, the design changes needed in the Equipment DB are stored in a ‘buffer’ file known as an inter-DB connection macro. Only when this macro is run by a member of the Equipment team, with Write access to the Equipment DB, are the changes implemented.
Assume that Project ABC has separate Piping and Equipment design teams. Assume that User P has Read/Write access to a Piping DB and Read-only access to an Equipment DB, while User E has Read/Write access to the Equipment DB and Read-only access to the Piping DB.
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When User P tries to set the Nozzle’s CREF, they receive a message telling them that they are trying to connect to a read-only DB and that an inter-DB connection macro is being created automatically. This macro, which stores the commands needed to set the CREF, is given a name with the format abc001.mac (where the macro number, 001 here, is allocated sequentially), and is held in the directory ABCMAC (or as defined by the project’s environmental variables).
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