Hi, Thanks to all for the replies regarding my database problem. In the end it was caused by duplicate blocks which affected marc_subfield_table and marc_word tables :-( Sadly mysql tells me that it "can't find any fields in the table marc_subfield_table", even though the file itself is many Mbytes in size. As an aside even e2fsck didn't report any errors until I ran it in conjunction with badblocks. The good side is that the system is not live yet, we are in the process of adding books (via z3950). To fix the problem I will have roll back to the latest good copy of those files that got corrupt. I now have three questions (my problem is that I don't really understand how the database is structured): 1. How do I determine which books (ie. ISBN and our barcode) have been added since that latest good copy. 2. How can I validate that the data base does not have any errors. 3. Is there a way of getting mysql to fix up those tables? Many thanks. tomasz kotula.