Relational data base control system using object oriented access logic to limit the data base access count, and corresponding method

• US 5,909,683 A
• Filed: 12/10/1996
• Issued: 06/01/1999
• Est. Priority Date: 11/05/1993
• Status: Expired due to Term

• Current Assignee: Jean-Charles Miginiac, Michel Planard
• Original Assignee: Jean-Charles Miginiac, Michel Planard
• Inventors: Miginiac, Jean-Charles, Planard, Michel
• Primary Examiner(s): Kulik, Paul V.
• Application Number:
  US08/640,915
• Time in Patent Office: 903 Days
• Field of Search: 707/4, 707/10, 707/100, 707/103, 707/203
• US Class Current: 1/1
• CPC Class Codes: G06F 16/289 Object oriented databases
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

The invention concerns a relational data base control system stored in a first storage unit (11) controlled in accordance with a first relational access logic, and including at least a series of records, each of the records being associated with an object including at least one variable and at least one method used to affect the value of at least one of the variables, data retrievals and/or modifications being made solely on the objects in accordance with a second object oriented access logic, the system comprising:

a second temporary object storage unit (15);

a control unit (14) including an automatic command generator unit (113) to be used in the data base according to the first access logic starting from commands corresponding to the second access logic;

a data transfer unit (16) transferring data in each direction between the first storage unit (11) and the second storage unit (15), data transfers between the first and the second storage units (15) being controlled by the automatic command generator unit (113) in order to limit the number of accesses to the first storage unit (11).

Claims

1. Method for controlling a relational data base limiting the number of accesses to the said data base, the said data base being stored in a first storage unit controlled in accordance with a first relational access logic and including at least one series of records, each of the said records including at least one data field, each one of the said records being associated with an object including at least one variable and at least one method for affecting the value of at least one variable, the said method including the following steps:

defining one or more object classes, each object class defining an object structure;

creating instances of a class, or objects, from one of the said object classes;

loading at least one object in the second temporary storage unit including the following steps;

read a record corresponding to one of the said objects, in the said first storage unit;

first transcoding of the said record to the said object as a function of the structure of the class of the said object, at least some variables of the said object corresponding to at least some of the said data fields in the said record;

write the said object in the said second temporary storage unit;

retrieval and modification of at least one variable of at least one object stored in the said second storage unit, in accordance with the said second access logic using the said methods;

save at least one record corresponding to at least one object stored in the said second storage unit, in the said first storage unit, including the following steps for each record;

read the objects corresponding to the said record in the said second storage unit;

second transcoding of the said object to the said record, as a function of the class structure of the said object, at least some variables of the said object corresponding to at least some of the said data fields in the said record;

write the said record in the said first storage unit, the commands to be applied to the said data base corresponding to the said first access logic being automatically generated from commands corresponding to the said second access logic given by an operator,

method characterized in that data retrievals and/or modifications are made solely on the said objects in accordance with a second object oriented access logic, and characterized in that it includes a step for managing a history of at least some of the said objects, associating at least two different values to at least one variable of the said objects, each of the said values being associated with two technical fields, a knowledge date field representing the date on which the value of the said variable was known, and an effective date field representing the date on which the value of the said variable became effective.

2. Method according to claim 1, characterized in that it manages work sequences called events, an event including at least two loading steps and/or at least two retrieval and/or modification steps, and terminating with a single save step.

3. Method according to claims 1 or 2, characterized in that it includes an access control step to the records in the said data base, preventing modification of the record in the said data base by locking it, when an object associated with the said record is stored in the said second storage unit and was modified.

4. Method according to claims 1 or 2, characterized in that it includes an automatic command generator step according to the first access logic, including management of a cache memory storing a series of previously generated commands.

5. Method according to claims 1 or 2, characterized in that at least some of the said objects include:

at least one stored variable corresponding to a data field in the record associated with the said object; and

at least one deductive variable, the value of which is determined during the said first transcoding step starting from the value of at least one data field in the record associated with the said object and/or the class structure of the said object.

6. Method according to claims 1 or 2, characterized in that a search for at least one object satisfying a predetermined condition is carried out in two steps:

step one corresponding to a search among objects stored in the said second storage unit; and

if the search is not terminated, a second step in which a search is made among records stored in the said first storage unit.

7. Relational data base control system limiting the data base access count, the said data base being stored in a first storage unit controlled according to a first relational access logic and including at least one series of records, each of the said records including at least one data field,

said system whereby each of the said records is associated with an object including at least one variable and at least one method that can act on the value of at least one of the said variables, the said system comprising:

a second temporary storage unit for objects;

a control unit including;

a unit for defining object classes, an object class defining an object structure, and means of creating instances of a class, or objects, from one of the said object classes;

a unit for retrieving and modifying at least one variable in at least one object stored in the said second temporary storage unit, in accordance with the said second access logic, using the said methods;

a unit for automatically generating commands to be used with the said data base, in accordance with the said first access logic, starting from commands corresponding to the said second access logic; and

a unit for transferring data in each direction between the said first storage unit and the said second storage unit, and associating a record in the said data base with the said objects by transcoding, the said record including at least one field corresponding to a variable of the said object, the said transcoding being a function of the class of the corresponding object,

data transfers between the said first and second storage units being controlled by the said automatic command generator unit so as to limit the number of accesses to the said first storage unit,

the system characterized in that data retrievals and/or modifications are made solely on the said objects in accordance with a second object oriented access logic, and in that it includes a unit for managing a history of at least some of the said objects, associating at least two different values to at least one variable of the said objects, each of the said values being associated with two technical fields, a knowledge date field representing the date on which the value of the said variable was known, and an effective date field representing the date on which the value of the said variable became effective.

8. System according to claim 7, characterized in that the same control means comprise means for managing locks preventing the modification of a file of the said database, when an object associated with the said file is stored in the said second storage means and has been modified by the said query and modification means.

9. System according to claims 7 or 8, characterized in that the said control unit manages work sequences called events, and the said automatic command generator unit sends a data transfer command from the said second storage unit to the said first storage unit only when an event is terminated.

10. System according to claims 7 or 8, characterized in that the said automatic command generator unit includes a cache memory storing a series of previously generated commands.