Re: Database storage approach (2)

[Arturo Tena <arturo directmail org>]

Hello!

Sorry if I'm late in the topic, here it goes:

**

Microsoft's Structured Storage and Compound Files (basis to OLE2)
technologies implements what you're proposing... a kind of persisten
object repository. But they think of it as filesystem.

i.e. a .xls file is really a filesystem. There are directories and files
in it. Microsoft calls `streams' to the files.

Basically, when you insert (incrust) a Excel document in a Word document,
it creates a subdirectory in the directory named `OLE'. In the new
directory stores some files, some are the actual information, some are
metadata. As a matter of fact, Microsoft users are able to do the kind of
queries that you purposed, all in the GUI, at least when using Office 95.
Just no one uses it... =) (BTW, it would be better to write that queries
in SQL, or better in XQL, the XML-SQL languaje).

Compound Files are a persistant object repository. Following with the
example, Microsoft Word knows only little things about the incrusted Excel
document: enough to store it and launch Excel app when it's double
clicked.

But this kind of file system is terribly broken, I mean it's far to be
fault tolerant, it's undocumented in its basis and altough it's seems to
me is unchanged from Office 4.2 to Office 97, nobody can say the same
about Office 2000.

**

Well, now what I think.

The first time I read your mail I liked the idea to substitute the file
system with a database. But, what benefits would be derived from that?

Search the metadata (i.e. open the files I edited yesterday) is not one of
them. That feature can be implemented easier in GNOME using XML, i.e.
gnumeric files would use a <METADATA> tag, with <AUTHOR>, <CREATIONDATE>,
<MODIFICATIONDATE> tags.

Fault tolerant is not one of them: one can think a better file system that
ext2fs, say ext2FTfs (Fault Tolerant), derived from the original ext2fs.

Distributed file system can be one of them, although coda (in Linux
kernel) is appearing now.

So, what benefits could be derived from the switching? The API, the GUI,
the different views, the command lines program that manages such creature
are easy to think and easy to do. The real task is justify it.


BTW, sorry for my broken English.

--
Arturo Tena
arturo@directmail.org


On Wed, 28 Apr 1999, Alexander Peuchert wrote:
> On Wed, 28 Apr 1999, James Henstridge wrote:
> > This sounds like a better idea.  Basically what you are sugesting is to
> > keep an index of the users documents (similar to the locate command) to
> > make searching for them quicker. But instead of just searching by
> > filename, you may want to search by mime type or keywords or some other
> > piece of metadata for the file.
> > 
> > Since we already have metadata support in GNOME, it may be possible to
> > modify GNU locate so that it can index on certain metadata keys as well.
> > It may also be worth changing the metadata functions in libgnome so that
> > they update the index as well (so you don't have to run an updatedb type
> > application every night).
> > 
> > Now with a GUI frontend to this modified locate command, we would have
> > quite a powerful search tool (it may be integrated with gmc or the search
> > dialog, which would be even better).
> 
> Okay, I have to admit it( shame on me!!!) I don't have a running GNOME
> installation at the moment :-(. So, I don't know how GNOME handles
> data-storage from the gui. If GNOME provides a dialog for loading/saving,
> it would be easy to just improve that instead of all apps ...
> 
> A filesystem tree is possible at the moment, but if you change to a
> >database view< or something like that, you don't have a folder hierachy
> any more. You can see all your documents, or filter them for specific
> things like date, etc.
> 
> - The views on the files is generated by a fast indexdb.
> - To store a document GNOME puts it into a default folder( maybe hidden)
> - some easy learnable filtering and sorting facility should be provided(
> does GNOME support wizards ?)
> - there is no hierarchy in the database approach
> 
> How about that?
> 
> alex
> 
> 
> > 
> > James.
> > 
> > --
> > Email: james@daa.com.au
> > WWW:   http://www.daa.com.au/~james/
> > 
> > 
> 
> Alexander Peuchert
> mailto:alexander@peuchert.de
> http://www.peuchert.de ( not very interesting yet ;-) )
> 
> 
> 
> 
> 
> -- 
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--
Arturo Tena
arturo@directmail.org