A brief introduction to the Multivalue Data Model

It is a multi-user, multitasking, multidimensional database management system. The MVDM is a complete environment that provides you with the capability to enter, modify, reformat, and retrieve information stored in data files.

• Organize data as simply as possible.
  
• Decrease application development time.
• Run applications faster than systems developed in other databases.
• Make users more productive with fast online access.
• Use minimal CPU, memory, and disk resources with its unique memory management and processing techniques.
• Run on a variety of hardware platforms.
• Fast data storage and retrieval.
• Efficient data storage and system usage.
• System and data security.
• Speedy development and simple maintenance of programs.
• A consistent environment which simplifies training.
• Portability to a broad range of hardware.
• Low cost.
• SQL Compliant; ODBC Ready.
• Truly scalable; database size is limited only by available disk space.
• All levels of normalization are supported.
• But, most importantly, the emphasis is on the business data model.

In developing a database management system that more accurately models real world information, the original MVDB developed by Pick Systems incorporated the following features in its data model that are carried to other MVDB vendor versions. The commonality of features give users of this database model the ability to move to what ever platform/vendor version that best meets their needs:

• Multiple values may be stored in the same field. A typical example is a phone number field, requiring more than one value. There may be a home number, work number, cellular number, pager number, and fax number.
• Values within values in a field. Values within a field may be further defined as subvalues. In some cases these are subdivisions of a value. But each subvalue may stand on its own, being designed into a database in order to provide an additional dimension to the data. An invoice has multiple line items. Each line item has a quantity ordered, quantity shipped and ship date. In order to accommodate multiple ship dates and quantities for each line item, subvalues are incorporated in the design of the application.
• Alternate access paths to the record. Indexes can be used as alternate keys to access the record. Access to any record via any data value is possible. Indexing provides faster access.
• Fields can reference data in other fields, records or databases.
• Special codes can be used in the field’s dictionary definition to refer to some other field in the record, record in the file, or record in another file in this database. Some examples are: Calculating the difference between this record’s “credit limit” and “credit used” fields, displaying “available credit.”