Data management method and system

• US 5,333,310 A
• Filed: 05/24/1990
• Issued: 07/26/1994
• Est. Priority Date: 05/30/1989
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Sakai, Naofumi
• Primary Examiner(s): Shaw, Gareth D.
• Assistant Examiner(s): Chavis, John Q.
• Application Number:
  US07/528,726
• Time in Patent Office: 1,524 Days
• Field of Search: 395/650, 395/700, 395/600
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2322 using timestamps
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A data management method and system for classifying shared data as new data or past data where the new data may be updated by processing and the past data may not be updated by processing. The data management method and system has a concurrency control, a central control and a sharing of data by a plurality of users wherein the past data is no subject to updating hereby precluding the need for lock processing by concurrency control of past data. In addition, together with query language, the capability of processing new and past data separately allows for an increase of concurrency control efficiency and a smoother user operation.

Claims

1. In a computer system having a database management computer system, a computer memory means, and an access control means which performs a concurrency control function for non-interfering sharing of data by a plurality of users, a data management method comprising the steps of:

storing a plurality of shared data records in the memory means, each record stored in conjunction with (i) a data name and (ii) a time parameter corresponding to the data name which are stored in the memory means;

setting in said database management computer system a time condition as a set time condition threshold for classifying data;

with the database management computer system, in response to access requests comparing the time parameter corresponding to a data name of each requested record with said set time condition threshold to classify the shared data record as one of (1) past data or (2) latest data in accordance with the comparison of the corresponding time parameter and the set time condition threshold;

storing the shared data records classified as past data nd the shared data records classified as latest data in a past data storage portion of the memory means and a latest data storage portion of the memory means, respectively; and

with the access control means, unlocking the shared data records classified as past data from the concurrency control function and allowing said past data records to be read from the past data storage portion of the memory means concurrently by said plurality of users without performance of the concurrency control function.

2. A data management method according to claim 1, wherein the set time condition is a predetermined time such that the shared data classified as the latest data become classified as past data after the predetermined time.

3. A data management method according to claim 1, wherein the set time condition is an occurrence of a predetermined event such that the latest data become past data with the occurrence of the predetermined event.

4. A data management method according to claim 1 further comprising:

with the database management computer system, moving latest data which is reclassified as past data from the latest data portion of the memory means to the past data storage portion of the memory means.

5. A data management method according to claim 4 further including a step of:

with the database management computer system, moving latest data into the past data storage portion of the memory means in response to a quantity of said latest data reaching a predetermined quantity.

6. A data management method according to claim 4 wherein the step of moving the latest data to the past data storage portion of the memory means is executed at a predetermined time each day.

7. A data management method according to claim 4, wherein said past data storage portion of the memory means includes a write once read many times memory.

8. A data management method according to claim 1 further comprising:

with the database management computer system, moving past data into the latest data storage portion of the memory means in response to a user'"'"'s request received through the access control means.

9. A computer system comprising:

first electronic data storage means for storing a plurality of data which is shared by a plurality of users, each shared data being a record with (i) a data name and (ii) a corresponding time parameter;

access control means for enabling a plurality of concurrent users to concurrently request access by the data names to the records of the shared data for reading and updating the shared data, the access control means performing a concurrency control function to provide for non-interfering sharing of records from the first data storage means by the plurality of concurrent users;

means for setting a threshold time condition;

classifying means responsive to a record request for comparing the time parameters of the requested record from the first data storage means which corresponds to the data name of the requested record with the threshold time condition to classify the corresponding shared data of the requested record as one of (1) past data or (2) latest data;

second data storage means for storing the past data;

means for transferring a record of the data classified as past data from the first data storage means to the second data storage means, the second data storage means being accessible by the access control means; and

means for inhibiting said users from updating the record of the past data, but allowing said past data to be read from the second data storage means concurrently by said plurality of users without the access means performing the concurrency control function.