COMPATIBILITY NO_TEST_LOCAL
In some environments (e.g., WIN32 / UNIX) the tests to determine if two files with different names are really different (or just accessed with different paths or aliases, etc.) may indicate the files are different, when in fact they are the same, if one of the names is based on a network reference and the other (through aliases, device mappings or SUBST commands) appears like a local file. If this occurs, the server may attempt to open the files as two physically different files.
Because of the possibility of a performance hit, COMPATIBILITY NO_TEST_LOCAL is available to turn off the check of whether a file is local or remote.