> On Wed, 3 Nov 1999, Edward S. Marshall wrote:
>
> > On Wed, 3 Nov 1999, Joe wrote:
> > > Does the linux kernel use a database? (retorical q here) I think
> > > not .. thus this patent is irrelevant to what is being done in
> > > kernel code.
> >
> > What would you call a filesystem, if not a database? :-)
>
> Just a filesystem or Pre-Database :-)
>
> Databases have mandatory transaction management. Means if process A
> accesses data fields process B has to wait till A finished (except both do
> reads only).
So any database without multi-user support doesn't count as a database?
Whereas a simple index like modern libdb2 does?
Somehow I don't think so.
>On some better databases you may work around transaction
> management - as on better filesystems you may activate transaction
> management (by locking files).
My definition says that some better databases *have* transaction
management (which, incidentally, is *not* primarily about multi-user
capabilities, but about commit and rollback).
> Not that I ever wanted mandatory t.m.... but I remember an angry professor
> who didn't like the idea of filesystems compared with databases - don't
> run into the same trouble :-)
The filesystem *is* a database - a *specialized* database. A typical Unix
fs, for example, allows for exactly one type of key (a pathname) and has
only BLOBs for non-key data fields (the file data). OTOH, an AS/400 file
system is just a view onto a relational database. (Even the active
processes are in that database.)
MfG Kai
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