On Fri, May 31, 2013 at 2:50 AM, Olaf Kluge <[email protected]> wrote:
> > in a table A there is a primary key, one column named ID. The second table > B > uses a single Field named ID_TableA, it references to the Table A (foreign > key) and this field is the primary key too. (1 to 1 relation). Now I have > two indexes for one Table-Column. Is this an problem? > A 1:1 relationship suggests a problem with the data model, but probably you've got a good reason for separating the information. Having two indexes on ID_TableA in table B will increase the cost of inserts, deletes, and updates that affect that column. If you need the foreign key constraint, there's no way to avoid a second index. Good luck, Ann IBPhoenix Tech Consultant column more expensive > > > > Thank you > > > > Best regards. > > > > Olaf > > > > > > > > [Non-text portions of this message have been removed] > > > > ------------------------------------ > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > Visit http://www.firebirdsql.org and click the Resources item > on the main (top) menu. Try Knowledgebase and FAQ links ! > > Also search the knowledgebases at http://www.ibphoenix.com > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > Yahoo! Groups Links > > > > [Non-text portions of this message have been removed]
