> Jeff wrote (see below)
>
> I agree. Many times (especially in the early days :)), I've managed to
> "repair" or recover data from half lost or damaged Image databases.
> The structure is visible, and well documented.
> The early relational DBMS's relied on C-ISAM structures, and (at least
> on UNIX) bypassed the file system in favour of their own raw
> partitions, making it almost impossible to "see" into the data, and
> therefore recover data from broken databases. The C-ISAM may have
> disappeared, but the internals are still a complete mystery.
>
> Long live Image! Viva HP3000!
>
> Neil (see you at the birthday bash(es)) Harvey
>
> With IMAGE, you can have all of your internal pointers, indexes, and
> other "relational" information completely hosed by a catastrophic
> failure and you can fully recreate the database from the raw data
> (well,
> with the exception of the bitmaps that show active/free status of
> records within a block).
>
> With an RDBMS, the data is scattered around everywhere, and many
> "tables" (depending on the specific software) are simply pointers to
> the data and not "duplicates" of the data itself (as in Image "keys"
> actually duplicating in each affected dataset).  Lose your pointers
> here
> and pray you have a recent backup.
>
> Jeff Kell <[log in to unmask]>