Indexed record locating and counting mechanism

Claim 1

A computer implemented method for searching an information tree of record keys with a search key to locate and retrieve a plurality of data records of a database held in the memory of a data processing system, wherein: each of said record keys represents one of said data records and comprises a string of a plurality ("s") of characters, the number s of said characters differing for different ones of said record keys; said search key comprises a string of a plurality ("k") of characters; said tree comprises a plurality of linked information nodes held in said memory, wherein each of at least some of said nodes comprises: (i) a field holding a string of the i-the through p-the successive characters common to all of the record keys represented by all of at least one subtree of said each of at least some of said nodes; (ii) a second field holding either a null pointer or containing a pointer to another of said nodes for which said i-the through p-the successive characters represent an initial portion of the respective key; (iii) a third field containing the total number of record keys represented by said field (i); and (iv) a fourth field containing either a null pointer or containing a pointer to another of said nodes which contains filed (i) similarly having j-the through n-the successive characters common to all of the record keys represented by all of at least one subtree of said each of at least some of said nodes, said j-the character greater than said i-the character in some alphabetical ordering; said method characterized by: (step zero) for each one of said nodes, comparing the string of the i-the through p-the successive characters of said search key with the record key character string held in the first field of said node, and (1) if said search key string does not match said record key string, then (a) if the fourth field of said node does not contain said null pointer then jumping to (step zero) using said node pointed to by said fourth field, but (b) if the fourth field of said node contains a null then immediately terminating search and returning a message signifying NOT FOUND from the search, but (2) if said search key string matches said record key string, then (a) if k=p, then immediately terminating search and returning the number stored in the third field of said node with a message signifying FOUND from the search, but (b) if k>p, then (i) if said second field contains a pointer to another of said nodes, then removing the first k successive characters from said search key and jumping to (step zero) using the node pointed to by said second field, but (ii) if said second field contains a null pointer then immediately terminating search and returning a message signifying NOT FOUND from the search.