How to build the index according to the string field??

How to build the index according to the string field??  I means the index implementation of a real database.If the field is one char or integer ,
 it is easy to compare the values to find the key's place . But string may be a few letters .How to denote the KEY(string) ??? I use B_Tree to build the index.
3x Received on Fri Jan 04 2002 - 06:28:10 CST