Re: Array of Integer

->From: grimes@access.digex.com (Seth Grimes) ->Subject: Re: Array of Integer ->Date: 5 Mar 1993 03:54:57 -0500 ->Reply-To: grimes@access.digex.com (Seth Grimes) ->Organization: Express Access Online Communications, Greenbelt, MD USA -> ->InterBase (from Borland) and Progress are both RDBMSes with an array ->datatype. I'd be interested in seeing more of an explanation of why this ->violates normalization. I (also) have the view that an array can be ->viewed as a single entity akin to a scalar field. -> I agree with you that most arrays, as used in scientific programming, are singular entities containing substructure. For example, consider ARRAY(3) OF FLOAT representing the x,y,z coordinates of a point in 3D space. I believe that this normalization requirement is more in response to the type of repeating groups that are used in Cobol. Consider an ordering system in which the programmer assumed that no more than 5 items will be included in a single order. The record (row) contains a 'num_items' field and five sets of item-specific fields. Everything is fine for 1 to 5 items, but the first time data entry clerks try to enter an order with 6 items, they run into problems. They are probably required to initiate a second order. First normal form, separating the general order info from the order-item info, eliminates the problem caused by some assumed max number of items per order. Regards, Alan +------------------------------+---------------------------------------+ | R. Alan Popiel | Internet: alan@den.mmc.com | | Martin Marietta, LSC | ( Please note: My opinions do not ) | | P.O. Box 179, M/S 5422 | ( represent official Martin policy. ) | | Denver, Colorado 80201-0179 | Voice: 303-977-9998 | +------------------------------+---------------------------------------+