----- Original Message -----
Sent: 23 July 2004 23:00
Subject: Re: [Hsqldb-user] Re:
DatabaseMetaData.getSchemas: bug?
Thanks Fred.
The issue and its extended discussion is age old
(HSQLDB 1.6).
The macinery for implementing ident by full
cat.schem.name is not that much.
Where (as always) the real issues enter are i
nthe following areas:
1.) What are we willing / do we need to specify
concerning the relationship between authorization descriptors and schema
descriptors?
In some systems, a schema is created per users
(implicit) and a schema cannot be created without an "owning"
user.
In other systems, schemas can be created
independent of users, but authorization descriptors can be associated with
schema descriptors.
This raises the question of how much, if at
all, we need to refince the current scheme of things regarding HSQLDB
authentication and authorization?
Will we need roles?
Will we need a cross-Database instance
Authentication/Authorization framework?
2.) What are we willing / do we need to specify
concerning the relationship between authorization descriptors and
catalog descriptors?
This is a larger and more "intrusive" issue
than schema support, simply because the current HSQLDB
Authentication/Authorization framework is based completely upon th notion of
Database instance scoped users (and roles, the only one being ADMIN,
currently)
The issue here is that there needs to be a
standard for what constitutes Authentication/Authorization in an SQL
environment that allows the simultaneous existence of several otherwise
isolated database (let's call them catalog) instances.
As Fred and I have dicussed several times,
there is a need for a session language that extend in scope above that of
any individual database session.
There is also a need, then, for a Session
context to carry about, among other things, the union of the
Authentication/Authorization tokens successfully obtained against each
catalog opened in session scope.
I have done some work in the HSQLDB MX package
to allow delegation of Authentication/Authorization to a java.security
(whole JVM) style facility, which can easily be adapted to the Java security
policy framework, if desired. It is also not difficult to implement a
cross-JVM ACL-based security manager, for JDK 1.1.
But, still, the devil's in the
details.
The main limiter here is that what
ever we specifiy regarding the behaviour and details of catalog support, it
should apply _only_ to the in-process perspective. There is a
perfectly acceptable standard that we can implement regarding the wider
scope (i.e. out-of-process federation/clustering), as described in the SQL
standards under the heading of SQL MED (management of external data).
I belive that Fred/Bela and crew still have some hopes to see this part
implemented as a standard but optional extention item, as exemplified by the
existence of the HSQLDB/R demonstration prototype.
Finally, the scopes of the
parser/_expression_/commandinterpreter facilities need to be expanded to be
able to handle cross catalog concerns.
Obviously, there are deeper, more troublesome
issues that remain unresolved and that we probably do not want to tackle
right away, such as cross-catalog referential integrity, cross-catalog
views, cross-catalog routine references, etc., mostly because the current
state of affairs does not guarantee that a referenced catalog will remain
available for the lifetime of the objects that reference it.
Well, that's my small 2 cents worth for
now.
Exciting stuff, everyone. I'm
looking forward to participating in the discussions and implementation, time
allowing.
----- Original Message -----
Sent: 23 Jul, 2004 11:18 AM
Subject: [Hsqldb-user] Re:
DatabaseMetaData.getSchemas: bug?
> Broadly agree with Blaine on this. Now that we support multiple
DB's in the
> same JVM, it is possible to support both catalogs and
schemas. At some point
> Campbell even mentioned what this would take in
terms of internal
> modifications--not a huge undertaking.
>
> I missed Jim's post. I must add that if you set the database
properties
> use_schema_names etc. you can use the "schema"."table"
pattern where the
> "schema" part is just ignored. Campbell described
this in his post.
>
> Fred
>
> ----- Original
Message -----
> From: "Blaine Simpson" <[EMAIL PROTECTED]>
>
Newsgroups: gmane.comp.java.hsqldb.user
> Sent: 23 July 2004
15:13
> Subject: Re: DatabaseMetaData.getSchemas: bug?
>
>
> Jim Caprioli wrote:
>
> > I use tablenames between
"quotes in HSQLDB like "schema.table". For
> > 'schema' SA it is just
TABLE. I had to support schema's somehow and I
> > didn't want to
give up on HSQLDB. IMO support for schema's should be
> > on
top of the list.
>
> I'm with Jim on this, but not having looked
into how much work it would
> be to do it
> right (i.e., being
able to assign and restrict storage space, etc., as
> well as
permission),]
> it could be that it is just beyond the scope of
HSQLDB.
>
> Maybe some other block would have come up afterwards,
but I have
> worked on a dozen projects where I couldn't set up HSQLDB
as a
> development env database
> because existing code,
procedures, infra depends upon independent user
> logins and
environments.
>
> My understanding is that HSQLDB is intended
for application-dedicated
> databases and therefore
>
simplifies things by not fully implementing schemas. Just as
text
> tables have greatly broadened
> the domain of application
of HSQLDB, full implementation of schemas
> could broaden the
>
domain from application-dedicated to enterprise.
>
> > I know
of several 'generic' tools that don't support HSQLDB because
>
> of lack of schema support.
> >
> > jimcap
> >
nilostep.com
>
>
>
>
>
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