System and method for storing, retrieving, and analyzing characterization data

• US 6,513,043 B1
• Filed: 09/01/2000
• Issued: 01/28/2003
• Est. Priority Date: 09/01/2000
• Status: Active Grant

• Current Assignee: Syntricity, Inc. (PDF Solutions)
• Original Assignee: Syntricity, Inc. (PDF Solutions)
• Inventors: Griffith, Steven William, Jelden, Alan Ward, Chan, Mark Che-hung
• Primary Examiner(s): Mizrahi, Diane D.
• Assistant Examiner(s): Mofiz, Apu M
• Application Number:
  US09/653,932
• Time in Patent Office: 879 Days
• Field of Search: 707/4, 707/7, 707/102, 707/206, 482/8, 702/130, 702/183, 600/300
• US Class Current: 707/802
• CPC Class Codes: G06F 16/284 Relational databases
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface

Abstract

A technique for efficiently structuring a database takes advantage of redundancy in data point conditions to reduce the time associated with the insertion of data points into a database and to reduce the amount of required storage space. The technique is particularly suited for semiconductor characterization data having a large number of test data points collected under repeated test conditions. The data point conditions are analyzed to inventory the different unique conditions associated with the given set of data points. Each unique combination of conditions is assigned a variable array, and each variable array element identifies a specific condition. The data point values are linked to variable set handles that represent the different variable arrays. In this manner, the data points can be inserted into the database without having to store each data point value with all of the corresponding conditions. Rather, the data point values are stored along with their respective variable set handles. The present invention also provides techniques for data extraction, management, and analysis, along with a database management system configured to carry out the various techniques.

Claims

1. A method for structuring a set of data points, comprising:

obtaining a plurality of data points, each having a data value and zero or more conditions associated therewith;

assigning a variable identifier to each unique condition associated with said plurality of data points, thereby assigning a plurality of variable identifiers;

constructing a number of variable arrays, each of said variable arrays representing a number of said variable identifiers;

designating a variable set handle for each unique combination of one or more of said variable identifiers, thereby assigning a plurality of variable set handles;

creating a VarSetInfo table that assigns said variable set handles to said variable arrays; and

,

using said VarSetInfo table to relate individual data values to one of said variable set handles.

2. A method according to claim 1, wherein each condition comprises a variable name and a variable value.

3. A method according to claim 1, wherein each of said variable identifiers comprises a variable array index identifier and a variable value index identifier.

4. A method according to claim 1, further comprising the step of encoding said variable arrays for compatibility with a database format.

5. A method according to claim 1, further comprising the step of writing said VarSetInfo table to a database.

6. A method according to claim 1, wherein said assigning step creates a VarInfo table that includes, for each unique condition associated with said plurality of data points, a variable name identifier, a variable value identifier, and one of said variable identifiers.

7. A method according to claim 6, further comprising the step of writing said VarInfo table to a database.

8. A method according to claim 1, further comprising the step of writing said individual data values with their related variable set handles to a database.

9. A method according to claim 8, wherein said writing step writes said individual data values with their related variable set handles to a file-based database.

10. A method according to claim 1, wherein said plurality of data points comprises characterization data.

11. A method for extracting data points from a database, each data point having a data value and at least one condition associated therewith, comprising:

(a) reading, from a first data storage location, a number of individual data values and a number of corresponding variable set handles;

(b) reading a number of entries from a VarSetInfo table maintained at said first data storage location, said VarSetInfo table including said variable set handles and a number of variable arrays respectively assigned to said variable set handles;

(c) reading a number of entries from a VarInfo table maintained at said first data storage location, said VarInfo table including, for each unique condition associated with a set of data points, a variable name identifier, a variable value identifier, a variable array index identifier, and a variable value index identifier; and

(d) creating a master table that relates each of said individual data values with a number of conditions.

12. A method according to claim 11, further comprising the step of writing said master table to a database.

13. A method according to claim 12, wherein said writing step writes said master table to a file-based cache database.

14. A method according to claim 11, wherein:

said variable arrays are initially encoded for compatibility with a first database format employed by said first data storage location; and

said method further comprises the step of decoding said variable arrays for compatibility with a second database format.

15. A method according to claim 14, wherein:

said first database format is compatible with character strings; and

said second database format is compatible with integer arrays.

16. A method according to claim 11, wherein:

said steps (a), (b), (c), and (d) are initially performed for a first set of data points;

said steps (a), (b), and (c) are repeated for a second set of data points; and

said method further comprises the step of formatting data values, variable set handles, VarSetInfo table entries, and VarInfo table entries for said second set of data points for merging with said master table.

17. A computer-readable data storage medium configured to accommodate a plurality of data points, said computer-readable data storage medium comprising:

a first data storage area defining a data point table that relates one of a plurality of variable set handles to each of a plurality of individual data values;

a second data storage area defining a VarSetInfo table that relates a unique variable array to each of said plurality of variable set handles; and

a third data storage area defining a VarInfo table having an entry for each unique condition associated with said plurality of data points, each entry including a variable name identifier, a variable value identifier, a variable array index identifier, and a variable value Index identifier.

18. A data storage medium according to claim 17, wherein each of said variable arrays is associated with a unique combination of conditions associated with said plurality of data points.

19. A data storage medium according to claim 17, wherein each of said variable arrays is encoded for compatibility with a format associated with said second data storage area.

20. A data storage medium according to claim 17, wherein at least one of said first, second, and third data storage areas is associated with a file-based database format.

21. A data storage medium according to claim 20, wherein:

said first data storage area is associated with said file-based database format; and

said second and third data storage areas are associated with a DBMS-based storage format.

22. A method for structuring a set of data points, comprising:

obtaining a plurality of data points, each having a data value and at least one condition associated therewith;

creating a VarInfo table that includes, for each unique condition associated with said plurality of data points, a variable name identifier, a variable value identifier, a variable array index identifier, and a variable value index identifier;

constructing a number of distinct variable arrays, each of said variable arrays being associated with a unique combination of conditions associated with said plurality of data points; and

creating a VarSetInfo table that assigns a unique variable set handle to each of said variable arrays, thereby, assigning a plurality of variable set handles.

23. A method according to claim 22, further comprising the step of relating individual data values to one of said variable set handles.

24. A method according to claim 23, further comprising the step of writing said individual data values with their related variable set handles to a database.

25. A method according to claim 24, wherein said writing stop writes said individual data values with their related variable set handles to a file-based database.

26. A method according to claim 22, wherein said constructing step constructs said variable arrays such that said variable array index identifiers correspond to said variable name identifiers and such that said variable value index identifiers correspond to said variable value identifiers.

27. A method according to claim 22, wherein sail constructing step constructs said variable arrays such that the number of different variable array index identifiers equals the number of different variable name identifiers associated with said plurality of data points.

28. A method according to claim 22, wherein said constructing step constructs a variable array having a variable value index identifier that represents an undefined condition for at least one of said plurality of data points.

29. A method according to claim 22, further comprising the step of encoding said variable arrays for compatibility with a database format.

30. A method according to claim 22, further comprising the step of writing said VarSetInfo able to a database.

31. A method according to claim 22, further comprising the step of writing said VarInfo table to a database.