==============

find all the tables that have a CreatorID column:

  SELECT DISTINCT TABLE_NAME 
    FROM INFORMATION_SCHEMA.COLUMNS
    WHERE COLUMN_NAME IN ('CreatorId')
        AND TABLE_SCHEMA='opensim';

=> yields assets inventoryitems prims primitems
as tables matching the column.

(note: replacing all creator ids like below still did not secure total ownership
to fred; some things retained their original creator.  how!?)

==============

replace all the creator ids with fred's id on ducky:

  update inventoryitems set creatorid = 'NEWGUID'

=> do for each of the tables.

==============

checking to make sure the changes to creatorid took effect:

  select * from assets where creatorid != 'YOURGUID'

=> there should be no matches after running a setting operation.

==============

if you have a more selective update to do, try replacing using a pattern:

  update assets set creatorid = replace(creatorid, 'OLDGUID', 'NEWGUID')

==============