Progress
Programming
Handbook
Logical Database Names
When you connect to a database, Progress automatically assigns that database a default logical name for the current Progress session. The default logical name consists of the physical database name without the .db file extension. For example, if you connect to a database with the physical name
mydb1.db
, the default logical database name is mydb1. Progress uses the logical database name mydb1 to resolve database references, and stores it in the compiled r-code of any procedures that you compile that reference themydb1.db
database.The Logical Database Name (–ld) connection parameter allows you to specify a logical database name other than the default.
The example below establishes the logical name firstdb for the physical database
mydb1.db
during the current Progress session:
When you develop and compile an application to run on the
mydb1.db
database, it is the logical name, not the physical name, that Progress stores in the r-code. You must use the logical name firstdb in your procedures (.p) to reference themydb1.db
database.Logical database names allow you to change physical databases without recompiling an application. To run a compiled application on a new physical database without recompiling, the new database must have identical structure and time stamp or Cyclic Redundancy Check (CRC) values for the tables accessed by the application and must be connected with the same logical name (or alias) used to compile the application:
The example above establishes the logical name firstdb for a new physical database
mydb2.db
.NOTE: Progress does not allow you to run the Progress Data Administration tool or character Data Dictionary against a database connected with the logical name DICTDB.A database connection fails if the logical database name of the database that you connect to has the same logical name as an already connected database of the same database type (Progress, ORACLE, etc.). If you try to do this, Progress assumes that database is already connected and ignores the request.
For information about the characters allowed in the logical name, see the Progress Startup Command and Parameter Reference.
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