Subject: Heterogenous database usage, anyone?

From: Omer Zak <[email-masked]>
Date: Sat, 30 Jul 2011 18:05:00 +0300

Is there anyone with experience with using an heterogenous database
setup?
There is some data, which is natural for RDBMS storage.
There is data which needs to be ACID-compliant (such as accounting
information).
There is data which does not benefit from the rigid structure of RDBMS
(such as documents and images).

Different kinds of data also differ in their
storage/retrieval/availability/searchability needs.

So it is reasonable to use a different DBMS technology to store each
kind of table.

However, sometimes it is needed to link together those different
technologies.  For example, if one wants to run a query on a multi-table
join where the tables (or their equivalents in technologies which have
no concept of a table) reside in different DBMS.

So heterogenous databases are not only multi-database installations.
They need to somehow cooperate with each other.

--- Omer

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---

From: Shlomi Fish <[email-masked]>
Date: Sun, 31 Jul 2011 19:44:24 +0300

Hi Omer,

On Sat, 30 Jul 2011 18:05:00 +0300

> no concept of a table) reside in different DBMS.

During my first year at the Technion (1997ish), I briefly worked for a company
called ISG (= “International Software Group” IIRC) that developed a product
called “ISG Navigator”. It may have been discontinued because the best I could
find about it on Google is:

http://h18000.www1.hp.com/products/quickspecs/10562_na/10562_na.HTML

which is from 2001 and mentions a lot of out-of-date technologies (and does not
mention many more recently popular ones).

In any case, what this ISG Navigator did was allow one to access data
(CRUD/etc.) from multiple different databases of different SQL and non-SQL
database servers, using the same unified interface, including crossing data
from multiple different sources. Some Perl mongers I talked with about that,
said that they'd rather not use something like that, because there would be a
problem of maintaining data consistency and integrity across different servers.
Maybe ISG Navigator had a way to overcome this.

Since then I have not really thought about this problem, and it's possible
there was too little demand for something like ISG Navigator to provide for
continued research into this issue.

Regards,

	Shlomi Fish

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