[DB-SIG] Result Set Inconsistencies

[Kevin Jacobs]

On Wed, 16 Jul 2003, Orr, Steve wrote:
> > DB-API is there to enable database access -- not hold your hand or 
> > write your applications for you. 
>
> Oh c'mon. Nobody said anything about writing apps for anyone. I can
> write wrappers to overcome the inconsistencies of the DB API
> implementations but the point is that I should not have to and the spec
> itself agrees with me in its second sentence!!! 

The API authors were very careful about _not_ specifying what kinds of
sequence type.  The fact that you want to fill in some extra details implies
that your needs differ from those that the authors intended.  This is not to
say that the spec is perfect, but this flexibility has been appreciated by
driver authors and has placed no undue burden on application writers.

> Why be timid about the spec? Improvement was obviously needed between
> 1.0 and 2.0... Are you saying the spec is an immutable type and is
> perfect as it stands?   :-)

Never!  I'm deeply unhappy about certain parts of the spec, and have spent a
great deal of time thinking about how to improve it meaningfully.  

> Developing on one database engine is easy but when you're developing
> apps to run on multiple database engines then you need consistency in
> the API.

My middleware framework currently supports 15 distinct DB-API drivers, and
none of them have the precise semantics that I want without glue logic. 

> Perhaps there's a complacency about this because there's not
> much multi-database development going on. Picture a LARGE app (many
> lines of code) written to support Oracle, Informix, DB2, SAPDB,
> PostGreSQL, MySQL InnoDB, etc. and picture having to learn ALL the
> idiosyncracies of all the DB API implementations and wrap something
> around them to minimize database specific code. Now picture not having
> to worry about it because the API spec was tighter in the first place. 

Sounds like every day for me.  I maintain over 500k lines of code in several
large financial applications that connect to many of the databases you
mention above, plus quite a few more.  And yes, I do have to worry about
driver idiosyncrasies, and frankly, the sequence type of the result set is
the least of my worries.

Now if you want to talk about more precise type specifiers, or sensible
semantics for bound query arguments, or a uniform type mapping
infrastructure, or anything else that really does impact complex and
heterogenious database enviornments, then you'll find I'm much more
interested.

-Kevin

-- 
--
Kevin Jacobs
The OPAL Group - Enterprise Systems Architect
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