db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Rick Hillegas <rick.hille...@oracle.com>
Subject Re: Database name length
Date Tue, 14 Sep 2010 12:50:35 GMT
Tiago Espinha wrote:
> Indeed, the length would still take two bytes and with these two bytes we'd be 
> able to take it up to 65535 in length.
> After talking with Kathey on IRC, I do agree that we might be deviating from the 
> standard with this. Can we still claim to be standard-compliant if we make an 
> exception for this. Can we pin this as an extension to DRDA?
> In truth, making this change would be as easy as changing a codepoint but I 
> think the issue here is standard compliance.
Hi Tiago,

DRDA is not one of Derby's governing standards. It is not mentioned in 
Derby's charter and the community has never voted to require DRDA 
compliance. We are free not just to extend DRDA but to flatly violate it 
if we need to.  We use DRDA because:

1) It is a public protocol which has been designed carefully.

2) It actually works, as demonstrated by a couple implementations.

3) When we need new network functionality, we often find supporting 
protocol already defined in this public, thoughtful, proven standard.

We do not make a general guarantee that any DRDA-speaking driver can 
communicate with the Derby server. I am fairly confident that the Derby 
client is the only DRDA-speaking driver that works with our server. It 
is certainly the only driver we bother to test. A driver written for DB2 
does communicate with early versions of the Derby server. However, we 
have not tested that driver with recent Derby versions.
> Kathey suggested that we'd turn this into a new JIRA issue and that we'd try to 
> get it through opengroup to change the standard to allow larger lengths.
Only one company has bothered to rent an expensive seat on the DRDA 
committee. All of the other committee members are merely advisors, who 
sanity-check but cannot initiate changes. Any change to DRDA would have 
to come from the seat-holder. His name is James Pickel and he works for IBM.

> I'm torn on this issue to be honest...
I am comfortable with extensions and deviations, provided that we 
document them.

Hope this helps,
> Tiago
> ----- Original Message ----
> From: Dag H. Wanvik <dag.wanvik@oracle.com>
> To: derby-dev@db.apache.org
> Sent: Tue, 14 September, 2010 0:02:49
> Subject: Re: Database name length
> Kathey Marsden <kmarsdenderby@sbcglobal.net> writes:
>> Does anyone know if there are other clients besides derby client that
>> might be working and expected to continue to work against Derby?
> I don't, but even if there were some, they would continue to work if
> they do indeed work with the present server, since the encoding of the
> db name length (2 bytes) would be unchanged, if I understood this
> correctly.
> Dag

View raw message