[dba-SQLServer] Schemas for separation of clients?

[Gustav Brock]

Hi Mark

Good points. The added precautions and potential issues may very well not be more "expensive" than the little money saved.

/gustav

________________________________________
Fra: dba-SQLServer <dba-sqlserver-bounces at databaseadvisors.com> på vegne af Mark Breen <marklbreen at gmail.com>
Sendt: 29. marts 2015 19:58
Til: Discussion concerning MS SQL Server
Emne: Re: [dba-SQLServer] Schemas for separation of clients?

Hello Gustav

I would not take this approach for a few reasons.

Before I start however, I see no technical reason why you cannot do it.  In
fact you could even keep one schema and just set permission s at dB table
level.  I only used multiple schemas one time and found it a pita.

1 reason is such complexity for small financial benefit.  You are going
against the normal use and it will be a struggle sooner or later.

2 security will sooner or later leak across the tables.  You goal is
segregation but you are putting everything in one dB and hoping nobody
makes a mistake in a year or two.

3 financially, the gain is not sufficient to justify the hoops you have to
jump through.  Unless the customer is paying pennies.  If the budget is so
low to force this approach then reconsider and use a cloud VM and install
SQL express and have separate dB's for everyone.

With aws and azure so cheap I would avoid the unconventional dB storage if
possible.

Hth

Mark
 On 29 Mar 2015 22:42, "Gustav Brock" <gustav at cactus.dk> wrote:

> Hi Arthur
>
> The main reason is, that at Azure you don't pay by the instance but by the
> database. The cheapest is B Basic at about USD 5 per month which is not bad
> but, obviously, if that can serve perhaps 50 clients' data it's even
> better. An even better deal - given low usage - is the S0 Standard level at
> about USD 14 per month for 250 GB database Space.
>
> As for the linking it should be quite easy; by default, a dbo.mytable is
> linked as dbo_mytable which you normally rename locally to mytable. So,
> when linking, you should link to client1.mytable, which will be given the
> name client1_mytable, which you rename to mytable. From that on, your
> application knows absolutely nothing about the tables of schema client2 etc.
>
> I cannot see why it shouldn't work, but I'm not a dba, indeed not
> regarding Azure SQL, so I'm looking for possible pitfalls.
>
> /gustav
>
> ________________________________________
> Fra: dba-SQLServer <dba-sqlserver-bounces at databaseadvisors.com> på vegne
> af Arthur Fuller <fuller.artful at gmail.com>
> Sendt: 29. marts 2015 15:13
> Til: Discussion concerning MS SQL Server
> Emne: Re: [dba-SQLServer] Schemas for separation of clients?
>
> Gustav,
>
> I don't have a precise answer for you. It's common practice in SQL Server
> to create "families" of tables; the AdventureWorks sample databases are
> show this ability off. But I have never tried to link to such a database
> from Access, so can't even guess how the table-names would appear in
> Access,
>
> It would seem that you are imposing a task on your potential users -- all
> that renaming. I'm also short on knowledge about Azure, but despite that, I
> must ask, Why not create one database for each user? Would that setup
> violate some constraint imposed by Azure's billing method?
>
> /Arthur
>
> On Sun, Mar 29, 2015 at 6:40 AM, Gustav Brock <gustav at cactus.dk> wrote:
>
> > Hi all
> >
> > Is it advisable and possible to create custom schemas in one database to
> > to hold otherwise identical tables separated for each client?
> >
> > For example, two tables:
> >
> >     client1.invoice
> >     client2.invoice
> >
> > Then assign rights for client 1 to schema client1 only, and vice-versa for
> > client2.
> >
> > When linking the tables from Access, client1 would see only one set of
> > tables, link these, and name them locally using the last part of the name
> > only: invoice.
> >
> > Would that be totally safe, so one client would never be able to see data
> > belonging to other schemas?
> >
> > The reason for asking is, that the current minimum size offered at Azure
> > (B Basic) is 2 GB which for the application, I have in mind, could hold
> > data for at least 25 clients. And the next step, S0 Standard, allows as
> > much as 250 GB. Of course, the DTUs also Counts but usage pr. client is
> > expected to be low.
> >
> > /gustav