• Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint
Share this Page URL
Help

VIII. Appendixes > B. The Quotient: An Additional Operation of the Relational A...

Appendix B. The Quotient: An Additional Operation of the Relational Algebra

The quotient of two tables is not used often, but has a very specific use. It arises when we wish to select those rows of a table that are sufficient to provide all possible values in certain columns. As an example, imagine a business that makes furniture. The database for this business has a table on the types of wood that they use, as well as on suppliers of wood and which types they supply. Examples are shown in Table B-1 and Table B-2 (of course, these tables would include more columns, but this is just to illustrate the point).

Table B-1. WOOD

Type

Mahogany

Red oak

Poplar

Walnut

Table B-2. SUPPLIER/TYPE

PREVIEW

                                                                          

Not a subscriber?

Start A Free Trial


  
  • Creative Edge
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint