It took me some time until I found why the program I’m working on is not working: the index (primary key) is not created on a memo field. Period.
Workaround? I created another field, in which I store the md5 hash (or any other hash, just make sure the relationship for the data you store in that field via that hash function is unique otherwise you will get the same hash for 2 or more different values) of the memo field which I make it the primary key.
ugly 😡
