A directory maps global names to a database file. GT.M processes use this mapping when storing and retrieving globals from the database. Multiple global directories can reference a single database file, and a database file can be referenced in multiple global directories, with some exceptions, as discussed in ChapterA 4: a??Global Directory Editora??. Use the Global Directory Editor (GDE) to create and maintain global directories.
In addition to mapping global variables to database files, global directories also store initial parameters used by the MUPIP CREATE command when creating new database files. GT.M uses environment variables to locate the global directory or, optionally database files.