Patent EP0111689A2 successfully refreshed from Google Patents.
EP0111689A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of storing a B-tree type index file on rotating media devices
Assignee: International Business Machines Corp
•
Filing: 1983-10-26
•
Granted: —
•
Expires: 2003-10-26
Abstract
Abstract index data is organized in main storage and on cyclically addressable media device such as diskette, disk or drum so that addresses of any index entry in the index is accomplished with one access mechanism seek plus on the average of one rotation of the media. The lowest two levels of the index structure are stored on the media device such that a next to the lowest level node and its related leaf nodes are cyclically addressable. The higher level of the index structure is organized as a B-tree index and stored in the main storage.
Inventors
- 👤 David H. Fritz
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 21:29
CPC Classifications
G; G06; G06F; G06F16/00; G06F16/90; G06F16/901; G06F16/9027
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
80 words
A method of storing a B-tree type index file structure in an operating memory and on a rotating media device in order to facilitate rapid retrieval of an index, characterized in that it comprises the steps of : storing the lowest two levels of said structure in said rotating media devicesuch that a next to the lowest level node and its related leaf nodes are cyclically addressable ; and storing a higher level of said structure in said operating memory.
Claim 2
Independent Claim
80 words
A method of storing a B-tree type index file structure in an operating memory and on a rotating media device in order to facilitate rapid retrieval of an index, characterized in that it comprises the steps of : storing the lowest two levels of said structure in said rotating media devicesuch that a next to the lowest level node and its related leaf nodes are cyclically addressable ; and storing a higher level of said structure in said operating memory.
Claim 3
Dependent Claim
100 words
The method according to claim 1 characterized by the steps of : determining d, the number of key/pointer pairs per index node ; allocating d+1 contiguous nodes on said rotating media device ; reading the keys and pointers of the object to be indexed in collating sequence and building the current lowest level of the index, the first node in the second preallocated node and the d th in the d+l st ; building the next higher level node in the first preallocated node ; for the remaining keys, performing the first four steps repetitively until all objects are indexed.
Claim 4
Dependent Claim
51 words
The method according to Claim 2 characterized in that it further comprises the steps of : if the first four steps were repeated <d times, building a root index, but if the first four steps were repeated ≥d times, recursively performing the entire procedure again optimumly indexing the previous "leaf" level.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.