Database Name Specification (db_namespec)

The database name specification uses a Uniform Resource Identifier (URI) format to identify the TFS and database name. The syntax for the naming convention is:

                [ server_uri ] database_name

Database Name Specifications

db_namespec Description
sales "sales" on default TFS using default transport.
tfs:///sales "sales" on default TFS using default transport.
tfs-tcp:// "sales" using TCP/IP with the default port number at hostname ""
tfs-shm://partition-01/sales "sales" using shared-memory to TFS named "partition-01"
tfs-tcp://[::1]:1530/sales "sales" using TCP/IP IPv6 using the loopback address on port 1530
tfs-tcp://[fe80::40da:bf3f:ae9f:fe87]:2000/sales "sales" using TCP/IP IPv6 to a specified machine on port 2000.
tfs-tcp:// "sales" using TCP/IP IPv4 to a specified machine on port 2000.

If you want to connect a remote TFS, you must first start the TFS Server. In the bin directory of the installation, run the rdm-tfs executable.

Union Database Name Specifications

A database union is a unified view of the data in more than one identically structured database. It makes the multiple databases appear as one. A union of multiple databases differs from having multiple databases open in that:

  • unioned databases must have identical catalogs
  • the union is viewed as one database, using one database number
  • it is read-only

Database unions are intended to be used with distributed databases or database mirrors to create a single, merged view of data that is owned and updated in separate locations or by separate entities. Database specifications are separated by a vertical bar (|) in the db_namespec.

Note that a database union is a union of different instances of the same database schema (i.e., definition) contained on separate TFS instances. This is not to be confused with the standard SQL UNION OF SELECT statements operation.

Example Union Database Open Specifications

rdm_dbOpen(hDb, "tfs-shm://partition-01/sales|tfs-tcp://", RDM_OPEN_READONLY);
open nsfawards as union of "tfs-shm://partiion-01", "tfs-tcp://":