[Zope-dev] SAP DB <--> ZODB ?

[Spicklemire, Jerry]

Kapil said:

> looks like it will instantly become the most advanced open source database

> out there. my current rankings of the general os rdbms  in terms of
features 
> postgresql->interbase->mysql  

Keep in mind that (even though) it is an effective "general os rdbms",
PostgreSQL was originally developed as an experimantal platform for 
testing concepts in the Object-Relational database realm. As such, 
it has some unique potential, especially in its ability to define 
and store Objects as _native_data_types_. 

Most of the effort and press related to PostgreSQL in the recent past 
has focused on adding SQL in place PostgreSQL's QEL, and improving 
stability and performance. Now that most of this important work has 
been accomplished, my hope is that some of the truly differentiating 
features can be showcased, e.g. a Zope Storage where an external SQL 
engine can directly interact with objects as native data. 

Imagine a SQL statement that updates every instance of a ZClass with 
new properties, or slipping a super-class in underneath (re-parenting), 
where it had never been before. 

also:

> the feature list of this database is astonishing
> www.sapdb.org
>
> to name a few
> subtransactions
> outer joins
> sql 92 compliant, possible modes for db2, oracle 7
> very nice prodecural sql language.
> lots of statistics information
> really rich set of standard functions
> scrollable cursors
> 
> this is a great candidate for a zodb storage

SAP DB is a fully licensed version of Software AG's (SAG) Adabas D, 
a descendant of SAG's venerable mainframe class system, Adabas C. 
Yes, SQL is fully supported, but SQL is after all a query language, 
not a physical model of the internal structure of an rdbms. 

This is not to say that Adabas, in any form, is any less of a capable 
system. Don't be surprised, however, to find something much closer to 
a network database under the surface, compared to PostgreSQL, which 
is about two generations newer, according to its "birth date" (1988?). 

Interestingly, many folks who have been around for several "database 
revolutions" see the network model as a very good choice for storage 
of "non-tabular" data types, such as objects, etc. On the other hand, 
that may be the result of lack of familiarity with the possibilities 
inherent in a true Object-Relational data model.

Later,
Jerry S.