[Zope] [FEATURE REQUEST] comment at the top of DTML Methodsand Documents

Jason Cunliffe jasonic@nomadicsltd.com
Fri, 25 May 2001 00:29:31 -0400

> > Thre are some contexts where one might
> > want ot store media fiesl in the ZODB up to cettain size or wher they
> > known to be static, while at a certain point they need to migrate to
> > LocalFS, ExtFile/Image etc. Documents are the same.
> I think this is heading in the wrong direction.... ZODB isn't magic, and
> neither is Persistence, they're both controllable.  There was a discussion
> while back about 'fine grained pack' of the ZODB -- that would really be a
> great feature, and it seems there's some work going on in that area.
> Perhaps each object could have a pack(date) method.  But aside from that,
> the only clear need I've seen for external storage is external (outside
> zope) access, which is a requirement independent of size or number of
> files...

Please clarify for me then..

ZODB is best when:
- There are more  READs than WRITEs.
Because of 'Undo', WRITE intensive designs will swell ZODB too quickly

External Storage is best
- There are frequent WRITEs.

- Very Large Files, or files which start off small and become very large
later, [Digital Video for example]. These couild more quickly combine to tip
ZODB past 2Gb limit [not a problem everywhere]

- Sharing data with others applications, sharing with Apache, whatever

- Need to leverage directly the filesystem's permissions [Linux & family]

What do you think?