Max users

  • Thread starter Thread starter Roger Sutter
  • Start date Start date
R

Roger Sutter

Is anyone aware of a limit on the number of users that
can be stored into the System.mdw?

We have a customer that wants to have 3000-5000 users all
using the same System.mdw. Where can I find out if there
is a maximum number of users that can be writen to the
file.
 
There is not limit on the amount of users in the mdw since
it stores the login names in a regular table inside the
system.mdw but it is governed by the normal MSAccess size
limit of 2GB (good luck getting that big with users
though). BUT WAIT!!! there is a maximum number of
concurrent users that can use a mdw of 255. The only way
to get around this is to make separate mdw files for
groups of users. 200 users per mdw... whatever. Each user
would have to modify their shortcuts that link
MSACCESS.EXE to the MDB with the MDW to spread out the
number of users per MDW. This is very hard to administer
though and I don't advise it.

BTW
I don't advise putting your security in the system.mdw.
Make your own otherwise you are applying security the same
security to every Access file you open or create with that
PC rather than for a specific file. Nothing is more
annoying to create a new Access file from scratch and you
still are prompted to enter a username and password.


-Cameron Sutherland
 
Cameron Sutherland said:
There is not limit on the amount of users in the mdw since
it stores the login names in a regular table inside the
system.mdw but it is governed by the normal MSAccess size
limit of 2GB (good luck getting that big with users
though).
True.


BUT WAIT!!! there is a maximum number of
concurrent users that can use a mdw of 255. The only way
to get around this is to make separate mdw files for
groups of users. 200 users per mdw... whatever. Each user
would have to modify their shortcuts that link
MSACCESS.EXE to the MDB with the MDW to spread out the
number of users per MDW. This is very hard to administer
though and I don't advise it.
Click to expand...

You can not increase the limit of 255 *concurrent* users, no matter
how many MDWs are used to define them.

BTW
I don't advise putting your security in the system.mdw.
Make your own
Click to expand...

This is not good advice. There is no way the average programmer can
devise a reliable home-grown scheme!

otherwise you are applying security the same
security to every Access file you open or create with that
PC rather than for a specific file. Nothing is more
annoying to create a new Access file from scratch and you
still are prompted to enter a username and password.
Click to expand...

You can achieve this using the Access /wrkgrp command-line parameter.

TC
 
Perhaps they all share the same PC? :-)

TC


GVaught said:
I'm just waiting for the next message? I have 3000-5000 users using a
database built by me, it keeps crashing and gets
corrupted.............................

I suggest whole heartedly that you should convince the powers that be to
invest in a stronger, more viable database to serve as the backend
especially since you will be dealing with 3000-5000 users. You could still
use Access as a front end or you could write something in VB or VB.Net to
serve as a front-end. I would NOT use Access.
Click to expand...
 
I was chewed up a but the response after me but only
because I didn't spend the time to fully explain my
response. Sorry, I hope this is clearer.
You can not increase the limit of 255 *concurrent* users, no matter
how many MDWs are used to define them.
Click to expand...
Maybe I should clarify that because there is a way but I
probably didn't explain enough. In any appliation of this
size I am assuming that you have split your files in to
back-end (data) and front-end (forms, reports...). If you
do this my suggestion was that you have multiple .mdw
files for however many users you need. So you might have
10 mdws with 200 concurrent users average giving you 2000
concurrent users. What I didn't add was that each of these
mdws need to be tied in to their own copy of the front-
end. So you might have 1 data source (Access, SQL,
ORACLE...) and 200 mdb front-ends with 200 mdws, one for
each. This level of administrative nightmares is obviously
why I said I wouldn't advise it.

This is not good advice. There is no way the average programmer can
devise a reliable home-grown scheme!
Click to expand...
I didn't mean re-invent some whole new programming method
to do your security I meant don't add your security into
the system.mdw file that comes by default with the Access
installation. Too many times I see new users
unsuccessfully run the security wizard and can't figure
out why later when they try to start a new database it
asks for username and password. For some new users its not
very clear. I was sugesting that they put all security in
a renamed copy of the system.mdw (recipes.mdw for example)
and tie your application file (mdb) to the security file
(mdw) with the /wrkgrp in a shortcut.

-Cam
 
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