Subject Re: [Firebird-Architect] Schemas
Author Martijn Tonies
Hello Claudio,

>> > - the catalog (system tables) lives in its own schema
>> (don't know how
>> > relevant it's, but I found it in other products)
>> Mostly "system" ;-)
> I found the SQL standard provides "definition_schema" (internal tables,
> available to the system only)


>and "information_schema" (the available views
> that the user can query to get metadata).

Yes, these days, SQL Server 2005 and MySQL provide such views,
extended with their own set of views and/or columns to make things fully
available to the user.

>> > - a schema can have security (and new privileges are needed
>> regarding the
>> > right to execute DDL, anyway)
>> A "user" in the database (not server wide) is automatically a
>> "schema" in
>> SQL Server. Not sure if this is a requirement or even wanted as such.
> But I think this changes in SQL Server 2005.
> says "Schemas are no longer equivalent to database users".

Correct, as in that you can create additional schemas, not bound
to users. Yet, a user (or role) has a default schema created.

>> > Now, who sees schemas as an urgent need and why?
>> In large databases, having schemas as namespaces can be very useful,
>> especially given the maximum of characters that can be used for
>> Firebird object names.
> Since Oracle uses (or used) shorter names (28 characters), I can see how
> important the feature was for Oracle, too.
> ;-)


Either way, I think you can understand the use of Schemas to group
items together.

With regards,

Martijn Tonies
Upscene Productions

Download Database Workbench for Oracle, MS SQL Server, Sybase SQL
Anywhere, MySQL, InterBase, NexusDB and Firebird!

Database questions? Check the forum: