🚀 go-pugleaf

In article <talrozen.5.31097BDA@math.tau.ac.il>,
   talrozen@math.tau.ac.il (Tal Rozenberger) wrote:
>What solution of fault tolerance to use (VINCA, SFT II, SFT III, Double Take 
>....) ?
>Can I write the application in MS-ACCESS ? What configuration does it need ?
>How to make sure to have data integrity ?
>How can I catch network error in MS-ACCESS ?
>What database to use ?
>Can I backup to tape while files (database) is opened ?
>How to lock the user to use only the application, and not letting him do 
>anything else ?
>What database support two-phase commit ?


I don't have all the answers to your questions, but have been playing with 
Access and Microsoft's SQL server lately.  Access works basically out of the 
box for File server/client database stuff.  There is also a complier so that 
you can give the enduser a standalone frontend and therefore limit what access 
they have to your database.  So that cares for a couple of your requirements.

If you visit Microsoft's web site and look around there a couple of articles 
on upsizing an Access database from fileserver/client to SQL.  SQL is 
basically an older product that needs backwards compatiblity with other front 
ends and has some special rules for using it.  If you are considering SQL as a 
backend, it would pay to find out the rules for upsizing BEFORE you start 
using Access.  Access does make it quite easy to upsize.

SQL allows you to datadump the data tables and then you can back up those and 
have a solid backup.  And since MS's SQL would reside on a WinNT server, there 
are avenues for tape backup there also.  Sounds like you might want to 
investigate this avenue more for your specific needs.

Lyle

In article <talrozen.5.31097BDA@math.tau.ac.il>, Tal Rozenberger
<talrozen@math.tau.ac.il> writes
>Can I write the application in MS-ACCESS ? What configuration does it need ?
>How to make sure to have data integrity ?
>How can I catch network error in MS-ACCESS ?
>What database to use ?
>Can I backup to tape while files (database) is opened ?
>How to lock the user to use only the application, and not letting him do 
>anything else ?
>What database support two-phase commit ?

Access is a pure PC application, has no forms of 'fault-tolerating' or
even 'error-recovery' support, and is only as secure as PC systems
allow.

Consider, on grounds of speed and cost of development and if the skill
are readily available, using it as the front-end of a client-server
application, but put all the difficult systems stuff, like fault-
recovery and security, on the SQLserver back-end.
-- 
Alan M. Dunsmuir

talrozen@math.tau.ac.il (Tal Rozenberger) wrote:

>I would like to start writing an application but I have some questions you 
>might know the answers.
>The project is to write an application (I though about MS-ACCESS) that will 
>work in network environment (I though Netware v3.12 or v4.1).
>The most important thing is data integrity and afterward high availability 
>(fault tolerance) in almost any case (I'll probebly need two servers in any 
>site with hot backup).

Don't even think of using Access.  Well, ok, using Access at the work
station end but use some kinda SQL server at the host.  Do *NOT* even
think of using Access on the server if it is so mission critical that
you're going to have two servers.

As to the "best" SQL server I have no experience in that area.

Tony
Tony Toews, Independent Computer Consultant
Jack of a few computer related trades and master (or certified) of none.

WRONG! If you use the built in security features of Access correctly you 
can protect everything from unauthorized meddling/snooping. To do this 
you need to create a new System.MDA file create an empty database, then 
import your existing database, set up your own admin account and set the 
security features you want on each object (the books give more detail). 
If done right its pretty good.

David Witteried

Lyle-
    As stated here the ADT does not compile an Access .mdb file.  It 
solely runs a crippled executable that doesn't allow access to toolbars, 
database window, etc.  This would seem to solve the security problem 
except that anyone with a full version of Access can still open that .mdb 
file right up.  The ADT is only useful in that it gives you license to 
distribute Access apps (w/ the crippled .exe) to people who don't own the 
full version of Access.  

-- 
Regards,
Tim Laverty
lavertyt%pk@mhs.elan.af.mil
or 72074,1722@compuserve.com

lgiese@mcs.com (Lyle Giese) wrote:

> There is also a complier so that 
>you can give the enduser a standalone frontend and therefore limit what access 
>they have to your database.  So that cares for a couple of your requirements.

Small clarification here.  The Access Developers Toolkit (ADT) is not
a compiler.  It's just a run time version of Access with no ability to
make any changes which allows you to distribute copies of your
database.  (This will require about 3-5 diskettes depending on just
how much work you spend on shrinking the files.)

As far as the access to your database, if you are using Access tables
this is a security issue and has nothing to do with the ADT.  Note
that security in Access 2 and 95 has been broken.  There have been
some very lengthy discussions in the newsgroup on that topic.  

As far as securing SQL back end servers I would assume that's much
better but I have no experience with them. 

Tony 
Tony Toews, Independent Computer Consultant
Jack of a few computer related trades and master (or certified) of none.