My understanding of AutoPlant is that it works with a database
Correct.
maintains a bill of materials
Maintains database entries for all specs and components used.
Generates BOM.
keeps all associated documents linked together.
Attempts; mostly successful.
not much for file sharing.
If you mean "file sharing sucks because of file bloat" that's not necessarily the case, certainly as a blanket statement for the suite of products that fall under the "AutoPLANT" umbrella.
It's true: Some models get grossly bloated, especially civil / structural, because of a failure of the software to perform proper house keeping on it's own data, though said failing doesn't happen consistantly (I cannot at present explain that). Typical manifestations are failure to delete unused / discarded groups and / or dictionary entries. I've seen extreme examples where it caused models to balloon to 100 MB or more because of millions++ (and I am not exagerating) of such refuse. Careful extrication of bogus data (i.e. leave good data) in these cases has frequently resulted in file reductions in the order of 100:1.
If you mean "not much for file sharing" in terms of "multiple people able to simultaneously edit a model", then yes, it is limited from my understanding (though I'm not involved in that aspect at all and am deductively drawing from discussions I've overheard).
/end of completely rivoting and useless info