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Re: debmake & dpkg



Ian Jackson:
> I have strong reservations about most of Christoph Lameter's
> proposals:

> > - Checksums stored in the .deb package and a function to verify the
> >   integrity of installed files.
> 
> My views on per-file checksums are well-known.

As far as I know, you don't like the idea.  May I ask why?  Maybe other
developers and users have different views?  I, for one, think that the
per-file checksums are a good idea, and not too hard to implement.  And
the competition (RPM) already does it...

> > - Get rid of all the single files in /var/lib/dpkg/info and use
> >   a database instead to provide faster operation (RPM is much faster

Noticed that too - most developers probably have nice Pentiums with fast
SCSI disks, but it's still not the case for most users.  So I think it is
important to improve the dpkg database speed.

> This is a very bad idea.  dpkg's databases are carefully designed to
> avoid bad lossage in case of disk overflow, bad sectors, &c, and to be
> manually fixable when required.  Typical database solutions do not
> have these important properties.

You're using the filesystem as a database, and typical filesystems don't
guarantee consistency after crashes, either.  So you can't be completely
safe without good backups anyway.  I do see your point, in fact I prefer
normal text files instead of binary databases (for the same reasons: can
be fixed using only vi, etc.), but at some point it just doesn't scale
well - in the future, there will be more and more packages...

Maybe we could somehow have the best of both worlds - for example, fast
db files generated from the current (slow but fixable) dpkg databases.
Something like that is done by "man" to speed up search for man pages.
I suspect (no hard numbers though) that most database accesses are reads
(not updates) so it might still improve overall speed (even if updates
are still slow), and the db files could always be generated again, if
anything bad ever happens to them.

Comments?

Marek


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