Hello! Thank you for replying!

On Sat, Oct 08, 2005 at 06:26:50PM -0500, Patrick K. O'Brien wrote:
> > A user can and should create "indices" - mappings from keys to objects (or
> > OIDs). These indices help to fetch objects; they also are there to be
> > iterated over, so the user does not need to fetch and test an every object
> > in the loop (which can be quite memory- and time-consuming) - it is enough
> > to iterate over an index and fetch only those objects that the user really
> > needs; the index iteration is usually optimized time- and memory-wise.
>
> IMNSHO the database should do these things automatically, based on a
> declarative syntax of the desired keys and indexes.

   I am not sure if it's possible to always do this automatically.

   BTW, I suspect that declarative syntax is a bigger area. I have heard
the words "ODMG" and "OQL" but never looked deeper. I thing OQL is a
declarative language for manipulating objects.

> Why shouldn't the database do more, like enforce referential integrity,

   What is a "referential integrity" in an OODB? Ensuring that no objects
store an index key to an absent (not yet created or deleted) object?

> Automatic persistence is the wrong approach and is a waste of time and
> effort.

   Why?! My experience is very limited but I don't see any major problem,
at least in theory. But if there are problems IWBN to know them now when I
haven't started a big job yet.

> The stuff in your list is all the good stuff.  Leaving all that to the
> user is why traditional object databases haven't had much of an impact
> on the world of database technology, imnsho.

   May be...

> Schevo provides all of
> that and much, much more.

   Has it enough documentation so I can start reading? I am at the beginning
of a long road. I'd like to try to use an OODB to replace an SQL DBMS in a
program (web-site); currently SQL DB contains about 800000 lines in the
main table, and SQL is a kind of obstacle - it is slow and is hard to
extend (switch from a pattern search to regexp search, e.g.)

> BTW, we are very close to a formal release of Schevo, which has been in
> stealth mode for about 4 years.

   Nice to hear! I have heard the words "Schevo", "PyPersyst", "object
prevalence" but never looked at the real code. It seems it's a good time
to start looking...

Oleg.
--
     Oleg Broytmann            http://phd.pp.ru/            phd@phd.pp.ru
           Programmers don't die, they just GOSUB without RETURN.