[Koha] Relationship between the MARC tables and the non-MARC ones:

[Hans Henderson]

I know the following is complicated, but I've tried to be as clear 
with my questions as my limited knowledge allows. 

As much as possible, I want to ensure that changes I make to the 
MARC-relevant data after it's all stored in Koha will make 
it back into any MARC records later exported, assuming the export 
functions are fixed in future revisions. I'm downloading MARC records 
with MARCedit and BookWhere, and preparing them in .mrc files to 
later import into the Breeding Farm. 

Do all the MARC fields existing in my records need to be linked to 
the non-MARC fields correctly first? 

Are all the data from the MARC records stored in the MARC tables "as 
is", even for those fields that have a -1 in the links 
pages? In other words, please confirm that "-1" just means that they 
don't display on the data-entry screens.

What if I make changes to these mappings after the import into the 
Breeding Farm, but before Biblios and Biblioitems have 
been created?

Please confirm that importing into the Breeding Farm doesn't create 
any records in the Biblio or Biblioitems tables.

And what needs to be done if changes in the links are made after 
Biblios and Biblioitems have been created? 

In either case (is the answer the same or different between the 
two?), will the data stored in the non-MARC fields then get 
copied to the MARC fields? Will the data in the MARC fields that used 
to be linked to the non-MARC fields still be in those 
MARC fields? In other words, does switching a link *move* or *copy* 
the data between the MARC fields?

Related question - if I later find more accurate/complete MARC 
records for existing biblio/biblioitems, import them into my 
Breeding Farm, choosing "overwrite" when Koha lets me know I already 
have that ISBN - Can I then update the relevant MARC 
fields for the already existing biblio/biblioitem records from the 
data from that new Breeding Farm record? Or do I need to 
make changes to existing records manually?

Thanks in advance for your help

Hans