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Posted to derby-user@db.apache.org by Andreas Kyrmegalos <an...@vivodinet.gr> on 2008/06/06 02:42:26 UTC
Database connection not bound to default database schema when authenticating
through LDAP?
Hello again,
I don't know what to make of this. I blame it to the late hour though.
After successfully authenticating user usertest through LDAP to
establish a connection , I get this message
ERROR 42Y07: Schema 'usertest' does not exist
when executing a statement against the database. The database's schema
is not 'usertest'. And the database
creator is not 'usertest' either.The same error is reported with other
user names.
I was under the impression that a database connection is bound to the
default database schema regardless
of the user name used to connect. Is this a LDAP related thing? Or is
it just the right time to hit the sack?
Andreas
Re: Database connection not bound to default database schema when
authenticating through LDAP?
Posted by Andreas Kyrmegalos <an...@vivodinet.gr>.
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
Re: Database connection not bound to default database schema when
authenticating through LDAP?
Posted by Rick Hillegas <Ri...@Sun.COM>.
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
Andreas Kyrmegalos wrote:
> Thanks Øystein,
> I was just checking that now too, with builtin authentication. Same
> result. My impression was that default schemas are attached to the
> database not the connecting user. So, that since a user has been
> authenticated and if there are no authorization locks in place there
> wouldn't be a need to set the schema each time a user connects.
> Something like a default behavior. But as you said the default
> behavior is have the connecting username as the starting schema.
> Thanks again. What I 'm trying to figure out is the rational behind
> such an approach. If someone could shed some light on this?
>
> Andreas
>
> Øystein Grøvlen wrote:
>>
>> The default schema is the same as the username, regardless of whether
>> it exists or not. You can use 'set schema' to switch to another schema.
>>
>
Re: Database connection not bound to default database schema when
authenticating through LDAP?
Posted by Andreas Kyrmegalos <an...@vivodinet.gr>.
Thanks Øystein,
I was just checking that now too, with builtin authentication. Same
result. My impression was that default schemas are attached to the
database not the connecting user. So, that since a user has been
authenticated and if there are no authorization locks in place there
wouldn't be a need to set the schema each time a user connects.
Something like a default behavior. But as you said the default behavior
is have the connecting username as the starting schema. Thanks again.
What I 'm trying to figure out is the rational behind such an approach.
If someone could shed some light on this?
Andreas
Øystein Grøvlen wrote:
>
> The default schema is the same as the username, regardless of whether
> it exists or not. You can use 'set schema' to switch to another schema.
>
Re: Database connection not bound to default database schema when
authenticating through LDAP?
Posted by Øystein Grøvlen <Oy...@Sun.COM>.
Andreas Kyrmegalos wrote:
> Hello again,
> I don't know what to make of this. I blame it to the late hour though.
>
> After successfully authenticating user usertest through LDAP to
> establish a connection , I get this message
>
> ERROR 42Y07: Schema 'usertest' does not exist
>
> when executing a statement against the database. The database's schema
> is not 'usertest'. And the database
> creator is not 'usertest' either.The same error is reported with other
> user names.
>
> I was under the impression that a database connection is bound to the
> default database schema regardless
> of the user name used to connect. Is this a LDAP related thing? Or is
> it just the right time to hit the sack?
The default schema is the same as the username, regardless of whether it
exists or not. You can use 'set schema' to switch to another schema.
--
Øystein