Initially we got no fatal job error but logical error due to truncation of values over 2700 bytes.
Increased limit using snapshot.max.string.size = 4000 in director.properties
Now we get fatal database error: ORA-12899 in EDQRESULTS schema, DN_255, COLUMN14 (actual 4001, maximum 4000)
1. Why we got no database error earlier with default snapshot character limit 2700 but got error when we increased limit? (column value was over 4000 characters in both cases)
2. Can we increase this over 4000 if database supports?
3. Can changing character encoding help here?
1. Changing the limit is to be done with caution. In this case I think you are falling foul of EDQ's no data handling which adds an extra character - set your limit to 1 character less.
2. No, because even if Oracle now supports >4000 characters, EDQ does not currently
If you really need to work with long fields, consider splitting them up before pulling them into EDQ.