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From Andreas Kyrmegalos <andrea...@vivodinet.gr>
Subject Re: Database connection not bound to default database schema when authenticating through LDAP?
Date Fri, 06 Jun 2008 14:31:16 GMT
Thanks for taking the time to consider my question and posting such a 
lengthy reply Rick. Luckily, I have found a way to force a default 
schema for my project's hibernate mappings and get things going just 
like I want them to be. For now anyway. Thanks again.

Andreas

Rick Hillegas wrote:
> Hi Andreas,
>
> I can see that for many applications it would be useful to have a 
> concept of a database-wide default schema, that is, a schema that all 
> users start out in when they get a fresh connection. That is not the 
> way Derby works. For Derby, the default schema is user-specific, not 
> database-wide. This is true even in the degenerate case of an embedded 
> application which does not run with authentication turned on: in that 
> case the username defaults to APP and the default schema is APP's schema.
>
> The 2003 SQL standard does not offer any guidance on this topic. 
> According to part 2, section 4.37.2 (SQL-session identification), the 
> default schema of a session is vendor-defined.
>
> I don't remember any deep reason about why Derby has this default 
> behavior. It may be nothing more complicated than the fact that the 
> original programmers were familiar with this default from previous 
> databases which they had worked on.
>
> Some databases let you bind a default schema to a username. See for 
> instance http://msdn.microsoft.com/en-us/library/ms190387.aspx. I 
> think it would be straightforward to build such a mechanism for 
> Derby--although this would take you into session startup logic and the 
> devil could be in the details. I think there are plenty of people 
> around who understand that logic and who could coach a newcomer 
> through this project.
>
> In the meantime, the only workaround I see is for your application to 
> force the schema to a default value when your application hands out 
> connections.
>
> Please pardon me if I have talked past your real concern.
>
> Hope this helps,
> -Rick

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