Re: How to create a DBMS from scratch?

Anthony.Youngman_at_ECA-International.com (Anthony Youngman) wrote in message news:<9a993dee.0211190404.1d0e356c_at_posting.google.com>...
> "Tony Ms" <tony_at_montgomery-smith.org> wrote in message news:<arbofj$ssl$1_at_knossos.btinternet.com>...
> > Visit http://www.xmldb.org/
> >
> Or www.maverick-dbms.org.
>
> You commented particularly about XML ... Note that putting XML into a
> relational database is nasty because most DBMSs can't handle nested
> data that well. Certainly I've heard that at a recent PostGreSQL
> conferences the people working on that DB have just thrown their hands
> in the air and walked away from the problem.

Can't say I agree with that. XML is just data.

I've been storing XML into Oracle and haven't had any problems.

However, I researched the items users will need to search on, and for those items I store those items in separate columns.

I'm storing the XML into varchar fields. It's just data. Ascii text.

However, Oracle 9 offers an alternative. It has an xml type which works like a varchar except that it provides for XPATH queries. I haven't used it because the DBA's haven't installed 9i client on our development machine.

I have experimented with the Oracle XDK. That's great for interacting with a DB and Oracle.

I figure the problems being referred to in this post have to do with making XPath queries available on data - not in storing XML.

>
> But MaVerick is a multi-value database, one of the Pick family (look
> also for the IBM databases UniVerse and Unidata, known collectively as
> U2, for jBASE, D3, mvBASE, Mentor Pro ...) and we keep having deja-vu
> every time we look at this sort of thing. Pick has thought in an XML
> paradigm since it was first designed, as the system known as GIRLS, in
> the early-to-mid 60s.
>
> So if you want to get into an environment where the XML way of
> thinking is second nature, look at the Pick-MultiValue stuff. We've
> been doing it for nearly forty years (not me personally, I'm not old
> enough :-)

This sounds like good advise.

In my stuff I store XML and fetch everything from the database with utility methods returning JDOM elements. The utility methods use metadata so the column names in the database become element names in the JDOM Element.

The XML is wonderful at getting you to reuse code (different queries) in different contexts. And if you HTML pages have 20 or 30 controls on a page, it's nice not to have to put each control in a database column. Another factor, around here deploying jsp's is a drawn out process, and by putting the XSLs into the database it saves a lot of redeploying.

As to the original question ...

making a DB from scratch ... there are already many alternatives.

The question is strange.

What language Perl, C, C++, JAVA? Why from scratch?

>
> Cheers,
> Wol
Received on Wed Nov 20 2002 - 00:24:19 CET