I've created a database in access 2007 that needs to be used by 3 users. I'm stuck because I don't know whether to place a copy on each users' computer or to place it on their SQL server. Placing it on the server would mean one access point which is desirable for data consistency but I don't know whether I need ActiveX. Don't know how to use it either. If I place it one each computer how do I work around the master file updates? Can somebody please break it all down, I'm a NEWBIE!!
Your question seems rather confused to me. You mention a SQL Server, but you don't say your application uses SQL Server for its data storage.
Thus, I can only assume that you have a single MDB or ACCDB file with your data tables and forms and reports all in the one file.
The only proper way to distribute this app is:
split it into front end (forms/reports/etc.) with linked tables that point to the back end (data tables only).
place the back end on your file server and relink your tables to point to the new location of the back end.
give a copy of the front end to each of the 3 users, who will run it from their desktop computers. If you're concerned about distributing changes to the front end, something like Tony Toews's front-end updater is very useful.
Others have jumped in to say that you should put the data in SQL Server, but most 3-user Access apps don't need the power of SQL Server. If you're not given administrative permissions on your SQL Server, it could be quite difficult to continue to alter your application's database.
On the other hand, if your database is going to grow to 1GB or more, or if you have strict security requirements, or if the data in your database is so important as to need completely failproof backups, then SQL Server would be a reasonable data store.
For most homegrown apps, not so much.
The "best" way I've worked this out is using Linked Tables in Access to go to SQL Server (since you stated you have that..?).
Using access as a front end in this scenario isn't the best thing you can do, but with 2007, it's a bit better than if you were a few versions back. Check out this article for info on linking Access into SqlServer:
Import or link to SQL Server data
One easy way is to use the EQL Data plugin: http://eqldata.com
That way you can give a copy of the database to each user, but users can sync the database with other users whenever they want. You can also access your tables and queries on the web.
Related
Guys I'm working on a local system project where I'd use Microsoft access as the database storage.
This application may be distributed among several users with different access layer control.
The direct method to secure the database from manual update is to put a password lock, however I came across this software today: https://www.accessrecoverytool.com/how_to_recover_access_password.html
It simply cracked my password with special character instantly.
May I know if there's any better way to secure a ms access mdb file?
Thank you.
there are many considerations when it comes to security. as E.v.A. has already posted, at a minimum, don't use the old .mdb file format and instead use .accdb or .accde (to compile the front) or.accdr (user only has runtime version).
whether or not the password method for the .accdb has also been publicly cracked I cannot say as I do not monitor such things. Assuming it is the data you are concerned about (rather than the front end code) - then the accdb can encrypt the data so that one must have a front end, with the embedded pw in order to see the data.
One can always put the back end data onto SQL Server Express to then rely upon the SQL Server's security feature set.
I am starting to create an MSAccess database, I have no Access experience - my previous experience is with MySQL and Oracle. Initially I had some difficulty coming to terms with the fact that MSAccess usually stores both the front end application and the Jet Engine database in the same file. It's different from what I'm used to. Plus the database will be shared over a network, and it just makes more sense to split the application from the data.
After some reading, I see that it is possible to store data in one file, and then link to the application elements in another file. Every article I've come across for this deals with splitting the database into two parts, after the database has already been made, and never discusses creating split database applications from the start. Is it because that would be a bad idea? I can't really imagine why, except that I've noticed that Access does not let me keep two database files open at the same time (it automatically closes one). So I am foreseeing a need to constantly to open and re-open files if I go down that route.
There is one practical reason why you might want to start with a single database. If you start with a front and back end file, you'll have to create tables in one database, then set up the link for each table manually.
This is not a big deal, but if you're just starting the system, you can save some busywork by developing the pilot system in one file, then splitting it. My assumption is you'll probably be making a lot of changes to the data structure at the outset; your work will go smoother if you're working in one file.
It is definitely a good idea to split the database before you deploy it to production. I'm not sure why you're having problems opening 2 Access files at once; this is not a restriction of Access.
You can create the two db files separately at the outset. I do that often. I seldom need both open at the same time in the Access interface. I only open the back-end database, which houses the tables, indexes, and relationships, to modify the design of those db objects. And those types of changes are relatively infrequent; most of the development workload is for the front-end db. To modify data in the tables, you can use the table links from the front-end db.
It is not a bad idea. You can have two files open at the same time, either open another Access instance or launch by double-clicking the second file. Make sure you have created a suitable back-end design before you start on the front-end.
It is more efficient to have it all in one file while you're alone to work on it. Once the database design is finalised, then you can split the db.
Splitting the db is usefull during testing as well: it allows you to reset your data to a known state in about 5 sec, just by copying a saved version of the back-end.
One of the best practices as specified by Microsoft for Access Development is splitting Access application into 2 parts; Front End that hold all the object except tables and the Back End that holds the tables.
The msdn page links there to the article Splitting Microsoft Access Databases to Improve Performance and Simplify Maintainability that describes the process in details.
It is recommended that in multi user environment the Back End is stored on the server/shared folder while the Front End is distributed to each user.
That implies that each time there are any changes made to the front end they need to be deployed to every user machine.
My question is:
Assuming that the users themselves do not have rights to modify the Front End part of the application what would be the drawbacks/dangers of leaving this on the server as well next to the Back End copy?
I can see the performance issues here, but are there any dangers here like possible corruptions etc?
Thank you
EDIT
Just to clarify, the scenario specified in question assumes one Front End stored on the server and shared by users.
I understand that the recommendation is to have FE deployed to each user machine, but my question is more about what are the dangers if that is not done.
E.g. when you are given an existing solution that uses the approach of both FE and BE on the server. Assuming the the performance is acceptable and the customer is reluctant to change the approach would you still push the change? And why exactly? For example the danger of possible data corruption would definitely be the strong enough argument, but is that the case?
It is a part of follow up of my previous question From SQL Server to MS Access 2007
The only drawback to leaving the individual user specific copies of the FE on the server is network performance. It won't make a difference as far as data corruption.
But you shouldn't share a FE between multiple users. This is prone to corruptions on the FE and other weirdness. Each user should get their own copy of the FE. Also you can't replace it with a new copy while users are using it.
A client was running for years with the FE on individual user folders on the file server but running msaccess.exe in a Citrix cluster. The IT staff didn't want to have anything updating the local hard drives of the Citrix cluster server systems.
As far as deploying the FE see the Auto FE Updater at my website. Huge changes coming in the next week to make it much, much easier for both initial server install and easier user initial install.
To keep the front-end on the server would more or less defeat the purpose of splitting the database. Putting the front-end on the desktop reduces network traffic since the application is not retrieved for each use, and allows the front end database to contain tables with data that is private to each user for storing settings or temporary data.
If you wish to avoid data corruption, it is important that each user should have their own copy of the front-end. Allen Browne offers more details on avoiding corruption in this article
There are a number of utilities available to update the front-end version on the desktop as required, or you can even write such a utility yourself.
I agree with the others. Keeping the fe on the server is not recommended. Just put a batch file on your server that does the push. When you have an update send a shortcut to the batch file via email. That is one of many solutions. Once you set it up it is not a problem.
Seth
As an Access 2007 Programmer using a Front End (FE) that is linked to a Back End (BE) database (a.k.a. Split Database) I have done both of the above. Sending an updated FE to users has other overhead, esp if third party controls or applications are used.
As for Citrix, back in Access 97 days, a Citrix manager was able to allow me to put one copy of the FE in a server file location. It would create a new instance for each user that logged in. We were able to use over 50 users with out any impacts. I must qualify this by saying the Access VBA code used efficient updates and transactions with roll-backs rather than just simple Select statements.
My problem today is Access 2007 running on a Citrix server (Windows 2003).
When I am the only person logged into Citrix, the application ( I picked a large complex report that creates a custom Excel spreadsheet via automation for the test) it runs within 1% as fast as running the FE from my XP workstation, and linking to the BE on the Citrix server hard drive.
But, when two or three people log into the Citrix Server, the same report takes three times as long. However, while two or three people are logged into Citrix, I can run my FE from my XP workstation and it runs exactly like the single-user on citrix.
A FE posted on a shared networked drive, shared by two or three users is NOT advised for this same reason. Access FE are not designed to be shared (* I will spare the details*). That is why people put a FE on each workstation and share one database (BE).
What I find lacking in Citrix is some good step-by-step "how-to" run Access FE on Citrix. Ideally, a single file could be posted. When a user loggs into Citrix, Citrix should make a copy of the FE and assign the resources (for Access) to that user's login.
I think this is exactly what MS Office does automatically or at least has instructions on how to do it.
If such a document exist, please post it. A programmer like myself would love to hand it to the Citrix Administrator. It would solve a lot of problems.
I have created an MS Access 2003 application, set up as a split front-end/back-end configuration, with a user group of about five people. The front end .mdb sits on a network file server, and it contains all the queries, forms, reports, and VBA code, plus links to all the tables in the back end .mdb and some links to ODBC data sources like an AS/400. The back end sits on the same network file server, and it just has the table data in it.
This was working well until I "went live" and my handful of users started coming up with enhancement requests, bug reports, etc. I have been rolling out new code by developing/testing in my own copy of the front-end .mdb in another network folder (which is linked to the same back-end .mdb), then posting my completed file in a "come-and-get-it" folder, alerting the users, and they go copy/paste the new front-end file to their own folders on the network. This way, each user can update their front end when they're at a 'stopping point' without having to boot everyone out at once.
I've found that when I'm developing now, sometimes Access becomes extremely slow. Like, when I am developing a form and attempt to click a drop-down on the properties box, the drop-down arrow will push in, but it will take a few seconds before the list of options appears. Or there's tons of lag in selecting & moving controls on a form. Or lots of keyboard lag.
Then, at other times, there's no lag at all.
I'm wondering if it's because I'm linked to the same back end as the other users. I did make a reasonable effort to set up the queries, forms, reports etc. with minimal record locking, if any at all, depending on the need. But I may have missed something, or perhaps there is some other performance issue I need to address.
But I'm wondering if there is an even better way for me to set up my own development back-end .mdb, so I can be testing my code on "safe" data instead of the same live data as the rest of the users. I'm afraid that it's only a matter of time before I corrupt some data, probably at the worst possible moment.
Obviously, I could just set up a separate back-end .mdb and manually reconfigure the table links in the front end every time, using the Linked Table Manager. But I'm hoping there is a more elegant solution than that.
And I'm wondering if there are any other performance issues I should be considering in this multi-user, split database configuration.
EDIT: I should have added that I'm stuck with MS Access (not MS-SQL or any other "real" back end); for more details see my comment to this post.
If all your users are sharing the front end, that's THE WRONG CONFIGURATION.
Each user should have an individual copy of the front end. Sharing a front end is guaranteed to lead to frequent corruption of the shared front end, as well as odd corruptions of forms and modules in the front end.
It's not clear to me how you could be developing in the same copy of the front end that the end users are using, since starting with A2000, that is prohibited (because of the "monolithic save model," where the entire VBA project is stored in a single BLOB field in a single record in one of the system tables).
I really don't think the problems are caused by using the production data (though it's likely not a good idea to develop against production data, as others have said). I think they are caused by poor coding practices and lack of maintainance of your front end code.
turn off COMPILE ON DEMAND in the VBE options.
make sure you require OPTION EXPLICIT.
compile your code frequently, after every few lines of code -- to make this easy, add the COMPILE button to your VBE toolbar (while I'm at it, I also add the CALL STACK button).
periodically make a backup of your front end and decompile and recompile the code. This is accomplished by launching Access with the /decompile switch, opening your front end, closing Access, opening your front end with Access (with the SHIFT key held down to bypass the startup code), then compacting the decompiled front end (with the SHIFT key held down), then compiling the whole project and compacting one last time. You should do this before any major code release.
A few other thoughts:
you don't say if it's a Windows server. Linux servers accessed over SAMBA have exhibited problems in the past (though some people swear by them and say they're vastly faster than Windows servers), and historically Novell servers have needed to have settings tweaked to enable Jet files to be reliably edited. There are also some settings (like OPLOCKS) that can be adjusted on a Windows server to make things work better.
store your Jet MDBs in shares with short paths. \Server\Data\MyProject\MyReallyLongFolderName\Access\Databases\ is going to be much slower reading data than \Server\Databases. This really makes a huge difference.
linked tables store metadata that can become outdated. There are two easy steps and one drastic one to be taken to fix it. First, compact the back end, and then compact the front end. That's the easy one. If that doesn't help, completely delete the links and recreate them from scratch.
you might also consider distributing an MDE to your end users instead of an MDB, as it cannot uncompile (which an MDB can).
see Tony Toews's Performance FAQ for other generalized performance information.
1) Relink Access tables from code
http://www.mvps.org/access/tables/tbl0009.htm
Once I'm ready to publish a new MDE to the users I relink the tables, make the MDE and copy the MDE to the server.
2) I specifically created the free Auto FE Updater utility so that I could make changes to the FE MDE as often as I wanted and be quite confident that the next time someone went to run the app that it would pull in the latest version. For more info on the errors or the Auto FE Updater utility see the free Auto FE Updater utility at http://www.granite.ab.ca/access/autofe.htm at my website to keep the FE on each PC up to date.
3) Now when working on site at a clients I make the updates to the table structure after hours when everyone is out of the system. See HOW TO: Detect User Idle Time or Inactivity in Access 2000 (Q210297) http://support.microsoft.com/?kbid=210297 ACC: How to Detect User Idle Time or Inactivity (Q128814) http://support.microsoft.com/?kbid=128814
However we found that the code which runs on the timer event must be disabled for the programmers. Otherwise weird things start happening when you're editing code.
Also print preview would sometimes not allow the users to run a menu item to export the report to Excel or others. So you had to right click on the Previewed report to get some type of internal focus back on the report so they could then export it. This was also helped by extending the timer to five minutes.
The downside to extending the timer to five minutes was if a person stays in the same form and at the same control for considerable parts of the day, ie someone doing the same inquiries, the routine didn't realize that they had actually done something. I'll be putting in some logic sometime to reset this timer whenever they do something in the program.
4) In reference to another person commenting about scripts and such to update the schema see Compare'Em http://home.gci.net/~mike-noel/CompareEM-LITE/CompareEM.htm. While it has its quirks it does create the VBA code to update tables, fields, indexes and relationships.
Use VBA to unlink and re-link your tables to the new target when switching from dev to prod. It's been to many years for me to remember the syntax--I just know the function was simple to write.
Or use MS-Access to talk to MS-Access through ODBC, or some other data connection that lives outside of the client mdb.
As with all file base databases, you will eventually run into problems with peak usage or when you go over a small magical number somewhere between 2 and 30.
Also, Access tends to corrupt frequently, so backup, compact and repair need to be done on an frequent basis. 3rd party tools used to exist to automate this task.
As far as performance goes, the data is being processed client side, so you might want to use something like netmeter to watch how much data is going over the wire. The same principle about indexing and avoiding table scans apply to file base dbs as well.
Many good suggestions from other people. Here's my 2 millicents worth. My backend data is on server accessed through a Drive mapping. In my case, the Y drive. Production users get the mapping through a login script using active directory. Then the following scenarios are easily done by batch file:
Develop against local computer by doing a subst command in a batch file
run reports against last nights data by pointing Y to the backup server (read only)
run reports against end of month data by pointing to the right directory
test against specialized scenarios by keeping a special directory
In my environment (average 5 simultaneous users, 1000's of rows, not 10,000's.) corruption has occurred, but it's rare and manageable. Only once in the last several years have we resorted to the previous days backup. We use SQL Server for our higher volume stuff, but it's not as convenient to develop against, probably because we don't have a SQL admin on site.
You might also find some of the answers to this question (how to extract schemas from access) to be useful as well. Once you've extracted a schema using one of the techniques that were suggested you gain a whole range of new options like the ability to use source control on the schemas, as well as being able to easily build "clean" testing environments.
Edit to respond to comment:
There's no easy way to source control an Access database in it's native format, but schema files are just text files like any other. Hence, you can check them in and out of the source control software of your choice for easy version control/rollbacks.
Or course, it relies on you having a series of scripts set up to re-build your database from the schema. Once you do, it's normally fairly trivial to create an option/alternative version that rebuilds it in a different location, allowing you to build test environments from any previous committed version of the schema. I hope that clarifies a bit!
If you want to update the back end MDB schema automatically when you release a new FE to the clients then see Compare'Em http://home.gci.net/~mike-noel/CompareEM-LITE/CompareEM.htm will happily generate the VBA code need to recreate an MDB. Or the code to create the differences between two MDBs so you can do a version upgrade of the already existing BE MDB. It's a bit quirky but works.
I use it all the time.
You need to understand that a shared mdb file for the data is not a robust solution. Microsoft would suggest that SQL Server or some other server based database would be a far better solution and would allow you to use the same access front end. The migration wizard would help you make the changeover if you wanted to go that way.
As another uses pointed out, corruption will occur. It is simply a question of how often, not if.
To understand the performance issues you need to understand that to the server the mdb file with the data in it is simply that, a file. Since no code runs on the server, the server does not understand transactions, record locking etc. It simply knows that there is a file that a bunch of people are trying to read and write simultaniously.
With a database system such as SQL Server, Oracle, DB2. MySQL etc. the database program runs on the server and looks to the server like a single program accessing the database file. It is the database program (running on the server) that handles record locking, transactions, concurrency, logging, data backup/recovery and all the other nice things one wants from a database.
Since a database program designed to run on the server is designed to do that and only that, it can do it far better and more efficently that a program like Access reading an writing a shared file (mdb).
There are two rules for developing against live data
The first rule is . . . never develop
against live data. Not ever.
The second rule is . . .never develop
against live data. Not ever.
You can programatically change the bindings for linked tables, so you can write a macro to change your links when you're deploying a new version.
The application is slow because it's MS Access, and it doesn't like many concurrent users (where many is any number > 1).
Two users wanted to share the same database, originally written in MS Access, without conflicting with one another over a single MDB file.
I moved the tables from a simple MS Access database to MySQL using its Migration Toolkit (which works well, by the way) and set up Access to link to those tables via ODBC.
So far, I've run into the following:
You can't insert/update/delete rows in a table without a primary key (no surprise there).
AutoNumber fields in MS Access must be the primary key or they'll just end up as integer columns in MySQL (natch, why wouldn't it be the PK?)
The tables were migrated to MySQL's InnoDB table type, but the Access relationships didn't become MySQL foreign key constraints.
Once the database is in use, can I expect any other issues? Particularly when both users are working in the same table?
I know this topic is not too fresh, but just some additional explanations:
If you want to use MS Access effectively, especially with bigger, multiuser databases, please do the following:
split your MDB into frontend application and backend (data only) files - you'll have two separate MDB files then.
migrate all the tables with data and structure into external database. It can be: MySQL (works very well, no database size limitations, requires some more skills as it's not MS technology, but it is a good choice in many cases - moreover you can scale your backend with more RAM and additional CPUs, so everything depends on your needs and hardware capabilities); Oracle (if you have enough money or some kind of corporate license) or Oracle 10g XE (if this is not a problem, that the database size is limited up to 4 GB and it will always use 1 GB of RAM and 1 CPU), MS SQL Server 2008 (it's a great pair to have MS Access frontend and MS SQL Server backend in all the cases, but you have to pay for license! - advantages are: close integration, both technologies are form the same vendor; MS SQL Server is very easy to maintain an effective at the same time) or Express edition (same story like with Oracle XE - almost the same limitations).
relink your MS Access frontend with backend database. If you selected MS SQL Server for the backend then it will be as easy as to use the wizard from MS Access. For MySQL - you have to use ODBC drivers (it's simple and works very good). For Oracle - please do not use the ODBC drivers from Microsoft. These from Oracle will do their work much better (you can compare the time needed to execute SQL query from MS Access to Oracle via Oracle ODBC and MS Oracle ODBC drivers). At this point you'll have solid database backend and fully functional MS Access frontend - MDB file.
compile your MDB frontend to MDE - it will give you a lot of speed. Moreover, it's the only reasonable form of distributing MS Access application to your end users.
for daily work - use MDE file with MS Access frontend. For futher MS Access frontend development use MDB file.
don't use badly written ActiveX components to enhance MS Access frontend capabilities. Better write them yourself or buy the proper ones.
don't believe into the myths that there are a lot of issues with MS Access - this is a great product which can help in may occassions. The problem is a lot of people assume it's a toy or that MS Access is generaly simple. Usually they generate a lot of errors and issues by themselves and their lack of knowledge and experience. To be successfull with MS Access it is important to understand this tool - this is the same rule, like with any other technology outhere.
I can tell you that I'm using quite advanced MS Access fronted to MySQL backend and I'm very satisfied (as a developer which is maintaining this application). My friends, the users are also satisfied as they feel very comfortable with the GUI (frontend), the speed (MySQL), they don't have any issues with records locking or database performance.
Moreover, it's important to read a lot about good practices and other people experiences. I would say that in many cases MS Access is a good solution. I know a lot of dedicated, custom made systems which started as an experiment in form of private MS Access database (MDB file) and then evolved to: splitted MS Access (MDE - frontend, MDB - backend) and finally to: MS Access frontend (MDE) and "serious" database backend (mainly MS SQL Server and MySQL). It's also important that you can always use your MS Access solution as a working prototype - you have ready to use backend in your database (MySQL - let's assume) and you can rewrite frontend to the technology of your choice (web solution? maybe desktop C# application - what you require!).
I hope I helped some of you considering the work with MS Access.
Regards,
Wawrzyn
http://dcserwis.pl
I had an application that worked likewise: an MS Access frontend to a MySQL backend. It was such a huge pain that I ended up writing a Win32 frontend instead. From the top of my head, I encountered the following problems:
Development of the ODBC link seems to have ceased long ago. There are various different versions floating around --- very confusing. The ODBC link doesn't support Unicode/UTF8, and I remember there were other issues with it as well (though some could be overcome by careful configuration).
You probably want to manually tweak your db schema to make it compatible with MS Access. I see you already found out about the needed surrogate keys (i.e., int primary keys) :-)
You should keep in mind that you may need to use pass-through queries to do more sophisticated SQL manipulations of the MySQL database.
Be careful with using lots of VBA, as that tends to corrupt your frontend file. Regularly compressing the database (using main menu, Tools | Database utilities | Compress and restore, or something like that --- I'm using the Dutch version) and making lots of backups is necessary.
Access tends to cause lots of network traffic. Like, really huge lots. I haven't been able to find a solution for that. Using a network monitor is recommended if you want to keep an eye on that!
Access insists on storing booleans as 0/-1. IMHO, 0/+1 makes more sense, and I believe it is the default way of doing things in MySQL as well. Not a huge problem, but if your checkboxes don't work, you should definitely check this.
One possible alternative would be to put the backend (with the data) on a shared drive. I remember this is well-documented, also in the help. You may want to have a look at some general advice on splitting into a frontend and a backend and code that automatically reconnects to the backend on startup; I can also send you some more sample code, or post it here.
Otherwise, you might also want to consider MS SQL. I don't have experience with that, but I presume it works together with MS Access much more nicely!
Gareth Simpson opined:
If it's only two users, then Access
should do just fine if you put the
.mdb on a shared drive.
Er, no. There is no multi-user Access application for which each user should not have a dedicated copy of the front end. That means each user should have an MDB on their workstation. Why? Because the objects in front ends do not share well (not nearly as well as Jet data tables, though there aren't any of those in this scenario using MySQL as the back end).
Gareth Simpson continued:
I believe the recommended max
concurrent users for Access is 5 but
on occasion I've pushed it past this
and never come unstuck.
No, this is completely incorrect. The theoretical limit for users of an MDB is 255. That's not realistic, of course, as once you reach about 20 users you have to program your Access app carefully to work well (though the things you need to do in an Access-to-Jet app are the same kinds of things you'd do to make any server database application efficient, e.g., retrieving the smallest usable data sets).
In this case, since each user should have an individual copy of the front-end MDB, the multi-user limits of Access/Jet are simply not relevant at all.
I know this doesn't answer your question directly, but it might be worth checking out the SQL Server 2005 migration tool for Access. I've never used the tool, but it might be worth using with SQL Server 2005 Express Edition to see if there are the same issues as you had with MySQL
Dont forget to put some type time/date stamp on each record. sometimes ms access will think "another user has changed or deleted the record" and will not allow you to make a change! I found this out the hard way.
In general, it depends :)
I haven't had a lot of problems when the application side has just been updating the data through the forms. You can get warnings/errors when the same row has been updated by more than one user; but Access seems to be constantly updating its live record sets all the time.
Problems can happen if Alice is already working with record 365, and the Bob updates it, and then Alice tries to update it with her changes. As I recall, Alice will get a cryptic error message. It would be easier for the users if you trap these errors and at least give them a friendlier error message.
I've had more problems when I was editing records in the VB code through RecordSets, especially when combined with editing the same data on forms. That's not necessarily a multi user problem; however, you have almost the same situation because you have one user with multiple connections to the same data.
If it's only two users, then Access should do just fine if you put the .mdb on a shared drive.
Have you tried it first rather than just assume it will be a problem.
I believe the recommended max concurrent users for Access is 5 but on occasion I've pushed it past this and never come unstuck.
On the other hand I did once use Access as the front end to MySQL in a single user environment (me). It was a singularly unpleasant experience, I can't imagine it would become nicer with two users.