@p.brc: how large is the db? Is this a small test db? (i.e., has it crossed the memory index threshold and actually persisted an index, or did schema alteration result in the first indexing job?)

@bkamphaus: Yes that might be the case. It is a tiny database on a dev server (the backup is only about 500KB ). Is there a separate directory setting where the temp files for the indices a written to. Or will they go into the data-dir (which is already writeable for the process)?