Just a note that I found out recently: Calling UPDATE BLOBTABLE SET BLOBFIELD = F_BLOB_UPPER( BLOBFIELD ) does not produce the desired results. If BLOBFIELD is null, then what is posted into the BLOBFIELD is the last non-null BLOBFIELD value returned by F_BLOB_UPPER (from the previous row). I believe you can resolve this problem by omitting null BLOBFIELDs, i.e. UPDATE BLOBTABLE SET BLOBFIELD = F_BLOB_UPPER( BLOBFIELD ) WHERE BLOBFIELD IS NOT NULL;