number of users

[sherwin]

how many users are allowed to access a database simultaneously? Thanks...

 

[boblarson]

Technically, you can have up to 255 users, but practically that number can
vary depending on the design of your database, whether you have it split as a
frontend/backend, and more.
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[Tony Toews [MVP]]

how many users are allowed to access a database simultaneously? Thanks...

Theoretically 255 is all the LDB file can handle. Practically
somewhere between 25 and 100 if you have a good quality network. If
you need more users or have other constraints then we strongly suggest
SQL Server, or equivalent, in which case there is no real limit to the
number of users.

Tony
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Tony Toews, Microsoft Access MVP
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[Arvin Meyer [MVP]]

how many users are allowed to access a database simultaneously? Thanks...

The statistical limit is 255. I have had 53 users with up to 75 database
front-end connections open to a single data backend. Of those users, up to 8
were from an ASP, web front end, up to 15 with Access front-ends running on
a Terminal Server, and the rest on a well maintained LAN. Most of the users
were editing or creating data. No problems.

 

[Larry Daugherty]

One saving grace that developers can embrace is that not all users who
might use their application at the same time will actually do so
unless it is the main application that all of that population uses
most of the time or if they all have the habit of opening applications
and letting them sit idle (as is increasingly common with modern
hardware and software) or in the special case of deliberately
stressing the application.

An example that comes to mind is the allocation of resources by all
phone companies in North America when step-by-step offices (pulse dial
only) were the norm. There were only sufficient "selectors" provided
to service 8 subscribers simultaneously out of the 200 subscribers
physically wired to that selector. The 9th and subsequent
simultaneous subscribers wouldn't even get dial tone. That was a rare
occurrance. Nobody noticed nor complained.

Once there is an awareness that a capacity limit is being approached
it is easy to move from Jet to SQL Server (for example). Once that
first transition is made then actually coding for SQL Server and
re-coding the Access front end will immprove throughput and reduce
bandwidth consumption.

HTH

 

[Arvin Meyer [MVP]]

One saving grace that developers can embrace is that not all users who
might use their application at the same time will actually do so
unless it is the main application that all of that population uses
most of the time or if they all have the habit of opening applications
and letting them sit idle

In the case of bound forms in Access, letting them sit idle can be a bigger
problem. Once the first keystroke is made, a lock is placed upon the record
or page. I solve that problem by forcibly logging off folks who are idle for
more than a reasonable time. That can vary from 10 minutes to 2 hours.

 

[Tony Toews [MVP]]

An example that comes to mind is the allocation of resources by all
phone companies in North America when step-by-step offices (pulse dial
only) were the norm. There were only sufficient "selectors" provided
to service 8 subscribers simultaneously out of the 200 subscribers
physically wired to that selector. The 9th and subsequent
simultaneous subscribers wouldn't even get dial tone. That was a rare
occurrance. Nobody noticed nor complained.

Actually that limit is still there even though it's much higher.
Some phone numbers have been programmed so they will be first in line
to get dial tone. Such as RCMP, hospital, town/city offices, etc.
This also extends to cell phones too I think.

I have taken some disaster training and am on call for situations such
as telecommunications outages and extensive power failures.

Tony
--
Tony Toews, Microsoft Access MVP
Please respond only in the newsgroups so that others can
read the entire thread of messages.
Microsoft Access Links, Hints, Tips & Accounting Systems at
http://www.granite.ab.ca/accsmstr.htm
Tony's Microsoft Access Blog - http://msmvps.com/blogs/access/

 

[Tony Toews [MVP]]

In the case of bound forms in Access, letting them sit idle can be a bigger
problem. Once the first keystroke is made, a lock is placed upon the record
or page. I solve that problem by forcibly logging off folks who are idle for
more than a reasonable time. That can vary from 10 minutes to 2 hours.

Yes, that places a lock on the record or page but it doesn't cause
corruptions or stress the MDB. I have had clients who've had power
failures with 15 or 20 users in the database and there was no
corruption or data loss. And I'm sure that some of those were in the
middle of entering data. Although I didn't explicitly ask.

Tony
--
Tony Toews, Microsoft Access MVP
Please respond only in the newsgroups so that others can
read the entire thread of messages.
Microsoft Access Links, Hints, Tips & Accounting Systems at
http://www.granite.ab.ca/accsmstr.htm
Tony's Microsoft Access Blog - http://msmvps.com/blogs/access/