How to create B-trees for multivalued attributes

B-TREE-P is usually used to index and browse single valued attributes, such as the names or ZIP codes used for the various examples in BTP/Branches #1. However, it is also sometimes desirable to create a B-tree that indexes multivalued attributes, so that the browser can display an "exploded" list of multivalued data, similar to the BY-EXP report option offered by Pick.

Multivalues can be indexed with B-TREE-P by following this simple rule: Call BTPINS once for each multivalue, with the multivalue's position number appended to the item's ID number by some arbitrary delimiter (usually an asterisk).