Maximum concurrent connections in ms access

What are the maximum con开发者_运维技巧current connections ms-access supports?

In theory 255, in practice well it’s depends. If they are mostly read only and the network you are on is fast then I have seen 100+ with no problems on a well written database. On the other hand I’m sure the same old horror stories of databases getting corrupt with 2 users will come up. Yes it can happen but if you make a good database and are realistic about what you do with it you can get a surprising number of users hanging off one.

In the long term you might want to look at the free (Express) version of SQL server for higher user counts.

Literally, "the Jet database engine versions 1.1, 2.0, and 2.5 can only be used by 10 client applications simultaneously on any one machine". Starting from Jet 3.0 there is no such limitation. See this link: http://support.microsoft.com/default.aspx?scid=kb;en-us;154869

In my experience 10 concurrent users starts causing problems. I'm sure there are examples w/ very small datasets working well w/ many users.

Access may be fine for some applications. There seems to be a lot of passion in this thread.

The key concept to understand here is that there is no server. EVERY QUERY will pull the ENTIRE table across the network.

If its a JOIN, EVERY QUERY will pull EVERY table involved across the network. That's because the JOIN engine is located on your desktop.

It doesn't matter where the access file is. At best, it is located on the primary user's desktop machine. Everyone else has to utilize the network to access the data.

If you have a 100k table and you want id #1042, you will pull 100k * Record length worth of data across the network and then filter out everything but #1042. It can't cache, because your coworker may have changed the next record you want to look at.

I don't think its necessarily the number of concurrent users on an Access DB. I think it's the number of people concurrently pulling sizable data chunks over the network each time they click a button.

Network load/Network latency will increase as table count grows, record counts grow,and user count grow. Possibly w/ a multiplicative effect. Compound this when you have offsite data centers (encryption), vpn users(encryption), users on different continents, etc. etc. etc.