Or a FileMaker search on complicated non-indexed fields (which are als o not cancelable)
That's a big one. Along those lines: a layout with lots of portals showing many unstored calculations,...
These kinds of slowdowns go hand-in-hand with two other factors:
- the load on the server at the time (# of users, # of those "expensive" actions that happen at that time)
- the server hardware (specifically the speed and # of cores/processors)
So sometimes these things seem to work great, especially on your development setup.
While not exactly a "user" action, a developer who's in the habit of modifying schema while users are attached can cause this phenomenon, especially if calculation fields are added / modified and then the schema are saved.
Besides changes to calc fields, turning indexing On for a new or pre-existing field on live files -- at the time the schema change is saved, the process of indexing the field(s) kicks in and takes time based on the number of records existing in that table. I've seen this in a system with hundreds of thousands of records, locking things up the file for several minutes.
Now that I think about it, a client performing a search on an unindexed field so that indexing has to be performed might have a similar impact, depending on the record count and field type.
Shutting down the server or unplugging the ethernet cable also causes these issues..