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Re: Web Storage & SQL

From: Giovanni Campagna <scampa.giovanni@gmail.com>
Date: Thu, 9 Apr 2009 18:47:04 +0200
Message-ID: <65307430904090947n14a795f6r152e591a7f5fbee@mail.gmail.com>
To: Boris Zbarsky <bzbarsky@mit.edu>
Cc: public-webapps@w3c.org
2009/4/9 Boris Zbarsky <bzbarsky@mit.edu>:
> Giovanni Campagna wrote:
>>
>> We have a standard SQL, and we have DBMS-specific extensions (for
>> SQLite, for MySQL, for SQLServer, etc.).
>
>> The latest version is "ISO/IEC 9075:2008 Information technology --
>> Database languages -- SQL", released in 2008, but actively being
>> revised, according to the ISO page.
>
> Sort of.  "Extensions" implies that as long as you write a query to the ISO
> standard in question the behavior will be the same in all databases and that
> you have to go out of your way to write non-interoperable queries.

Yes. With extensions I mean writing "start transaction" instead of
"begin", using the backquotes instead of double quotes for
identifires, using INET and spatial data types, using table options...

> This is
> not the case.  A query written based on that ISO standard has different
> behavior in different databases, in many cases.

This is obviously an implementation bug, and should be corrected in
the DBMS, not in the browser or in the web page.

> So just telling web authors "write queries based on this standard and they
> will work" is not sufficient.  Let's ignore the fact that most web authors
> wouldn't be able to even get their hands on this standard to see whether
> their query complies with it without paying a fairly hefty sum [1].

We have tutorials and guides for that

> You could also require UAs to implement queries exactly per this standard.
>  Vladimir mentioned as a possible option in his original post.  This is
> definitely the way forward (with either this SQL definition or some subset
> thereof)

But some extensions are useful (like spatial data types or
non-transactional database engines): I don't see why we should not
allow them, in a vendor (browser or dbms) specific form.

>> As usual, if you want interoperability, you use the existing,
>> implemented, standard (or you ask the ISO to produce an updated
>> standard with new features), else you use extensions.
>
> Use of the existing standard by authors doesn't give interoperability.

Again, this is an implementation bug, not something that should affect authors

> -Boris
>
>
> [1]
> http://www.iso.org/iso/search.htm?qt=9075&searchSubmit=Search&sort=rel&type=simple&published=on
> tells me that to get just the parts of ISO 9075:2008 that are obviously
> necessary to be able to do anything whatsoever will cost me either about
> $290 or $770 depending on what's in part 2 of the spec.  I'm assuming none
> of parts 3,4,9,10,11,13,14 are relevant to our use case; this is probably a
> good assumption for most of them.  That's for getting a PDF, of course; the
> PDF on CD prices are somewhat higher, and there seem to be no other
> provisions for looking at this specification.

Unfortunately, these are the problems of ISO standards. We cannot change that.


Giovanni
Received on Thursday, 9 April 2009 16:47:40 GMT

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