When I said what I said about SQL and RDBMSs and that other thing I said about tree structures and hierarchies in RDBMSs this is what I meant (mostly).
I was browsing DB Engines (valuable resource this is) looking at popularity rankings for various database systems and comparing features looking for hot new tech when I started digging into Object Oriented Databases again.
I searched for (open source?) Object Oriented Database engines more intensely nearly 6 years ago (DB Engines wasn’t around back then) and I was disappointed to find that there was little to no popular demand for pure OODBMSs. Every damn google search or wiki lookup spat out RDBMSs conjoint twin little brother, the ORDBMSs (Object-Relational Databases) but that didn’t fit the bill I had in mind.
At that time I did find one open source and pure OODBMS
EyeDB which currently looks like a dead project (damn!).
I might have missed (read disregarded) some niche products (read proprietary)
I don’t remember reading about
InterSystems Caché or the underlying technology
MUMPS which looks very ahead of its time.
But I do remember some important players on the market: Versant and Objectivity which were (and still are) proprietary, as well as another intriguing approach
JADE a proprietary full-stack system including a DB.
But why all the fuss? Why not just RDBMS like every one else (freak)?
It felt very strange to me that developers would go gentle into that good night. Developers are inherently lazy creatures which would rather spend 20h automating a 22h long repetitive task than blankly toil away at the repetitive task.
Why would they ever accept to learn an entirely new set of concepts about handling data, read about the mathematics behind it, and mentally bridge the gap between one concept and the other every damn day of the rest of their careers (a repetitive task)?
Why jump through all of these hoops when an OODBMS can achieve the same performance as any RDBMS (or better) and also do away with the systems’ impedance mismatch of using an ORM? Not to mention all the work of building and maintaining an ORM having to debug for it or to limit your access to DBMS features because of the ORM.
Why bother writing a
CREATE TABLE which contains virtually the same thing as your
class declaration? …and then endeavor to burden yourself with manually keeping every future change from the
TABLE or the
class in perfect sync with one another? ..DRY anyone?
Versant Object Database for example describes an awesome schema versioning capacity in their product which allows you to simply give the DB the newly compiled class structure and VOD will handle updating old entries to the new schema (eagerly or lazily depending on your requirements).