When designing BLOB storage tables, use the following pattern:
 – create one table containing only the BLOB column and a timestamp column
 – store all BLOB-s in this table
 – create a set of separate tables containing additional data; also add a timestamp column
   to these tables.
The rationale:
 – usually one needs to detect the BLOB has been changed or only the additional data has been changed;
   this way it is easier to detect what has changed, the BLOB or the additional data only.