Re: RFD: schemas and different kinds of Postgres objects

Bill Studenmund <wrstuden@netbsd.org> writes:
> On Wed, 23 Jan 2002, Tom Lane wrote:
>> Bill Studenmund <wrstuden@netbsd.org> writes:
> Why not? What's wrong with either schema.foo.function (==>
> function(schema.foo)) or foo.schema.function (==> schema.function(foo))?
>> 
>> Neither is wrong in isolation, but how do you tell the difference?
>> More to the point, given input x.y.z, how do you tell which component
>> is what?

> ?? Depends on how we do it. As I see it, we have four cases. In the
> x.y.z.p.q, we have:

> 1) No table name, but a function name. It's a function call.

> 2) A table name, but no function name. It's a table reference.

No, you're missing the point.  Which of x,y,z,p,q is the name we
are going to test to see if it is a table or function?  And which
of these names is a schema name --- if you don't even know that,
it's hard to argue that checking to see if some name is known is
a well-defined operation.

> When you started this thread, you said you were thinking about
> "implementing SQL schemas." Are these "SQL schemas" going to follow the
> spec or not?

If you use only the SQL-defined operations, after setting up any
configuration variables we may invent in the way we will document as
necessary for SQL-compatible behavior, then you will get SQL-compatible
behavior.  I do not think that precludes having an underlying
implementation that sees the world differently than SQL does and
supports non-SQL behaviors too.  (For that matter, I'm sure there is
text somewhere in the spec that points out that the spec intends to
define user-visible behavior, not implementation.)
        regards, tom lane