db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Knut Anders Hatlen <knut.hat...@oracle.com>
Subject Re: Database name length
Date Mon, 13 Sep 2010 11:53:11 GMT
Tiago Espinha <tiago.derby@yahoo.co.uk> writes:

> Thank you Knut, for your reply.
> Your point #1 is correct. As for point #2 and #3 just a small correction. It is 
> all characters falling outside the *US-ASCII* encoding that will get a length 
> lower than 255 characters as anything other than ASCII requires more than just 1 
> byte to encode. I'm fairly sure that at this point we do not support ISO-8859-1 
> through the client driver as these characters (the extended ones like áéó etc) 
> fall outside US-ASCII. So hopefully this won't break anything as we didn't 
> support these characters previously.

I think we do support this. At least, this code ran fine on my machine
with Derby and created a database named áéó:

    Connection c = DriverManager.getConnection(

> As for your suggestion of increasing the length of the field, I'm not sure 
> that's an option. This length limitation is imposed by the DRDA specification 
> and the ACR unfortunately didn't change this. On the ACR it reads "As of DDM 
> Level 7, the RDBNAM can accommodate an RDB name of up to 255 bytes in length, 
> and its format will vary depending on the length of the RDB name". So 
> essentially, we could easily support a much larger RDB name on Derby but the 
> specification forbids it.

DRDA does allow product-unique extensions. I have a hard time seeing any
downside with extending the protocol here. Sending a longer string than
what a strict reading of the spec permits sounds like a lesser evil to
me than disallowing network access to the database.

Knut Anders

View raw message