I have two users in P6, both need access to all projects, both need to see and be able to write to the dashboard and inside schedule of all projects (there are approx 1000 projects and the odds of both being in the same one are slim). Will this cause a database issue or have the integrity of the information suffer? What really happens if they both write to the same project at the same time? Please help.
Who ever writes last will overwrite the first entry. It is very unlikely that you will have issues as the users would literally have to change the same value within a refresh cycle of each other. Its acutally a selling point that multiple users can be in the same schedule.
Also, a message will appear if you try and schedule a project someone else has open. I would instruct them that if that happens they need to double check their work. They should be regularly hitting F5 to refresh their data.