Good question. Although I would want to move away from relational
databases too, if there is an RDBMS and one wants to query it, what
would I aim for? If you look at XQuery, you will see an example of
what I would definitely NOT aim for. Although the user of such a
language might very well be a technical person, instead of starting
with mathematics (relational calculus, relational algebra) I would
suggest starting with language. The mathematics of language is more
complex than the mathematics of relations, particularly simple
relations (such as 1NF tables).
If you look at the history of data persistence prior to Codd's 1970
ACM paper, you will see several attempts at this. One I have studied
of late is GIRLS (Generalized Information Retrieval Language and
System), specified by Don Nelson and implemented by several folks with
the most famous being Dick Pick. This GIRLS language was specified a
full 40 years ago and lives today in many IT shops under a variety of
about 10 different names, including IBM's UniQuery and Retrieve (for
UniData and Universe respectively). This language is flawed, as are
all, but so very close to what I would think would be a good approach.
It was written at TRW in order to make it so that the military in
Viet Nam could query their data without technical folks in the field.
It went into production in 1969 with the US Army. Prior to the end of
the cold war, it was used by the CIA to track (the associated
database) and query about Russion spies in the US.
I would suggest ditching the entire relational model (as both overly
simplistic in its theory and overly complex in its implementation) and
start with English (that is one of the other names for the GIRLS
language). Note that language is also the starting point for putting
data in XML documents, but it sure doesn't seem to be the starting
point for XQuery, eh?
--dawn
Dawn M. Wolthuis
www.tincat-group.com
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TIP 9: the planner will ignore your desire to choose an index scan if your
joining column's datatypes do not match
