Re: [ubl-dev] UBL and a functional SQL schema

[Aleksei Valikov <valikov@gmx.net>]

Hi.

> Agreed - that's why I mentioned the XML storage type - 
> such as Oracle has - which pre-indexes the XML content
> for you on INSERT (you pay the piper upfront with 
> slower storage times) - but then you can access the
> content "normally" using SQL extensions and XPath
> expressions to reference the content directly.
> 
> Internally its using those mini-indexes at the record
> level it created to index into the content directly.
> Neat, simple, easy, fast!

I agree that XML storage types have certain advantages when compared to 
LOBs, but XML indexing is effective only for a limited subset of 
queries. If you querying logic fits this subset - fine, if not, those 
will be users who play the piper. At the same time structural storage of 
XML data allows you tune and optimize your SQL (or HQL) queries, 
introducing targeted indexes, partitions and so on.

I have nothing against XML databases or XML features of industrial DBs, 
I simply want to point out that architecture of the XML storage facility 
is a strategic design decision. And it is not as easy as "store XML in 
CLOBs" or "atomize XML and store it in tables".

Bye.
/lexi