>you can (a) get all of the records belonging to company N

and (b) select count (*) where companyid='N'

exactly what I thought

>The number does not tell you how many records exist, however.

I never thought that

>you can NOT use a generator number as a record enumerator

I never thought that

> Third. If you have one generator for each company, you will have

multiple records in the table having the same ID.

the row is uniquely identified by (company_ID, ID)

> That's three bads.

I have still to see the first one :)

>How are these numbers to be used? Knowing that might shed more

light on why you think you need different generators for each
company...

very easy: say that every company stores digital pictures in the
database. They want every picture be uniquely identified. This ID
will be given by their private generator.

However - for privacy sake - no company must be aware of the activity
done by others. If I store a picture today and it is given no 100 and
store another picture tomorrow and it is given no 200, I know that -
or I could think that - others stored roughly 100 pictures.

This is exactly the info that cannot leak "outside".

Every company must know the no of its pictures (the application will
issue a "select count(*)..") and nothing else.

All in all I stay with the idea that I need one generator for every
company: I see no other solution.

Thank you

Duilio