When you invoke SDA, by using the DCL commands ANALYZE/SYSTEM
    or ANALYZE/CRASH_DUMP, SDA first executes commands from an
    initialization file if one exists, before prompting the user
    for commands. The initialization file is commonly used to read in
    symbol tables and define keys for SDA commands.

    First, SDA searches for an initialization file using the logical
    name SDA$INIT. If this file is not found, then SDA searches for
    the file SYS$LOGIN:SDA.INIT. If no initialization file is found,
    or after the initialization file SDA commands have been executed,
    SDA starts accepting interactive user commands from the "SDA>"
    prompt.