Abstract: A method and apparatus for increasing the speed of a search through leaf nodes of an inventive key index tree structure, known as a "Q-tree". The present invention identifies "decision-bits" within leaf node entries and uses these decision-bits to accelerate searches for a particular record or for a record adjacent to which a new record is to be inserted. A decision-bit is a particular type of distinction-bit having the smallest value and associated with a search key a greater value then the keys associated with other distinction-bits of the same value within a specified search range. Each decision-bit divides a search range into "left" and "right" parts. One of the two parts will constitute a "new" search range. A "quit-bit" having an ordinal number equal to the value of the decision-bit for the search range, is tested. If the quit-bit is "on", then the right, or greater value, part becomes the new search range. Otherwise, the left, or lesser value, part becomes the new search range.

Abstract: A method and apparatus for increasing the speed of a search through leaf nodes of an inventive key index tree structure, known as a "Q-tree". The present invention identifies "decision-bits" within leaf node entries and uses these decision-bits to accelerate searches for a particular record or for a record adjacent to which a new record is to be inserted. A decision-bit is a particular type of distinction-bit having the smallest value and associated with a search key a greater value then the keys associated with other distinction-bits of the same value within a specified search range. Each decision-bit divides a search range into "left" and "right" parts. One of the two parts will constitute a "new" search range. A "quit-bit" having an ordinal number equal to the value of the decision-bit for the search range, is tested. If the quit-bit is "on", then the right, or greater value, part becomes the new search range. Otherwise, the left, or lesser value, part becomes the new search range.

Abstract: A method for sorting data in a computer data storage system that has particular advantages in implementing a key index tree structure. The sorting method uses buffer-size substrings to sort strings of key records into a linked list structure that can be directly transformed into an index tree. The sorting method also may be used for sorting large sets of data records in place on a computer storage system. The method further integrates prefix compression and suffix compression of key records with the sorting method to reduce the number of input/output operations required to create a more compact key index tree structure.