jfathman@aol.com wrote in
news:1119540879.171417.276240@g44g2000cwa.googlegr oups.com:
[color=blue]
> We are considering a project that requires implementing a database
> (Windows PC based) that would be shared by a small number of
> users. The database would store events output by our networking
> device, and any of the users could generate reports based on the
> stored event data.
>
> This would be for small, low-cost systems, not large enterprise
> systems with big commercial databases and dedicated servers.
>
> Any of the user PCs could be uniquely identified as the master,
> and then the other user PCs would access the shared database on
> the master PC via the LAN.
>
> We are thinking in terms of an Access database that runs on one
> user machine, and that is accessible from the other user machines.
> We are thinking of using Crystal Reports to both generate
> predefined reports, and optionally allow a more sophisticated user
> to define and produce his/her own reports. The integration
> language is likely to be VB6.[/color]
Since you seem to not be intending to run the database in Access
(otherwise you'd be idiots to consider Crystal Reports when you
could instead use the Access report writer, which after all these
years is still superior to every competitor so far as I can see),
you're not really using and Access database at all, but instead a
Jet MDB file. You may have used Access to create the MDB file, but
if you're not building your application in Access, you're not really
using an Access database.
So, you're just asking about where to store your data.
Jet works fine for small shared database storage, as long as:
1. you are managing your connections carefully, hitting the back end
only for a few milliseconds for each operation to add or update
data.
2. you don't exceed the limits of what Jet can do. The theoretical
limit on number of simultaneous users of a Jet database is 255, but
that's not realistic. Most folks around here would say that once you
have 15-25 simultaneous users you would probably make life easier on
yourself by moving to a server database engine.
From your description, though, it sounds like it's only a reporting
applications, with only a single PC capturing and adding the data,
and with no data updates. That would likely be the kind of
application where Jet could exceed the usual 15-25 users, as the
latter numbers assume that the users are updating and adding data.
Keep in mind that choosing Jet 4.0 does mean that you're in the OS's
protected file space, as Jet 4 is used for the Active Directory
database, and is thus part of the OS. This is both bad and good --
it means that if the PC has an old version of Jet, you can update it
only by following certain procedures, such as having certain Windows
service packs in place before applying a Jet service pack. This was
a problem with unpatched Win2K -- you couldn't apply Jet 4 SP6 until
you'd upgraded to at least Win2K SP1. On the other hand, you also
get the benefit of the Windows service packs updating the Jet engine
for you, since Win2K SP3 already includes Jet 4 SP6, and I assume
that the later Win2K service packs include SP8 (the latest version I
know of). WinXP will have a different history and set of
restrictions (I think it shipped with SP6 or later, so probably
never needs patching).
I don't consider any of these problematic issues, however. They are
just something you need to consider if you are dealing with older
machines -- you definitely don't want to use Jet 4 with anything
earlier than SP6, though.
--
David W. Fenton
http://www.bway.net/~dfenton
dfenton at bway dot net
http://www.bway.net/~dfassoc 
