I have inherited a (rather large) database, which at the moment is only ever accessed by a single user. In the future I want this to be accessible to multiple users at the same time (which can be done using Filemaker Network).
I am concerned that multiple user access may break much of the functionality (for example searches, which change records in tables). What other things should I look out for which could cause multi-user problems?
Searches should just be queries - those shouldn't impact other users above/beyond overall performance.
Updates should be reflected across all users - that's the benefit of using filemaker for multiple users. If you need to keep recordsets for distinct users then you will need to look at making significant changes.