DATABASE SYSTEM, METHOD OF MANAGING DATABASE, DATABASE,STRUCTURE, AND COMPUTER PROGRAM

• US 20110087697A1
• Filed: 05/28/2009
• Published: 04/14/2011
• Est. Priority Date: 05/30/2008
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Kamimura, Junpei, Kashiwagi, Takehiko
• Granted Patent: US 9,104,711 B2
• Time in Patent Office: Days
• US Class Current: 707/769
• CPC Class Codes: G06F 16/2228 Indexing structures
• CPC Class Codes: G06F 16/2255 Hash tables

Abstract

Disclosed is a database system capable of effectively updating data in a database at a high speed. The database system includes: a storage unit that stores a database including an entity data group and at least one identifier table having only a plurality of fixed-length data; and a data processing unit that receives a query and performs data processing on the database on the basis of the received query. The identifier table has a plurality of data identifiers that uniquely indicates the plurality of entity data as the fixed-length data.

Claims

1. A database system comprising:

a storage unit that stores a database including an entity data group containing a plurality of entity data and at least one identifier table having only a plurality of fixed-length data; and

a data processing unit that receives a query and performs data processing on the database on the basis of the received query,

wherein the identifier table has, as the fixed-length data, a plurality of data identifiers that uniquely indicate the plurality of entity data.

2. The database system according to claim 1, wherein

a storage area allocated to the identifier table is different from a storage area allocated to the entity data group.

3. The database system according to claim 1, wherein

values of the data identifiers are output values of a hash function that outputs a fixed-length bit string when the entity data is input.

4. The database system according to claim 1, wherein

the database includes a conversion table indicating a correspondence relation between pieces of position data indicating the storage areas of the plurality of entity data and the plurality of data identifiers, and

the data processing unit selects entity data from the entity data group using the conversion table and performs the data processing on the basis of the selection result.

5. The database system according to claim 4, wherein

the position data is an address designating the absolute position of the storage area of the entity data.

6. The database system according to claim 4, wherein

the position data is an offset designating the relative position of the storage area of the entity data.

7. The database system according to claim 1, wherein

data identifiers for searching having the same values as the plurality of data identifiers are added to the plurality of entity data, and

the data processing unit searches for the data identifiers for searching, selects the entity data on the basis of the search result, and performs the data processing on the basis of the selection result.

8. The database system according to claim 1, wherein

the plurality of data identifiers are stored in continuous storage areas of the storage unit.

9. The database system according to claim 1, further comprising:

a defragmentation unit that reads the plurality of data identifiers from the storage unit and writes the read data identifiers to continuous storage areas allocated to the identifier table when the plurality of data identifiers are dispersed and stored in a plurality of discontinuous storage areas.

10. The database system according to claim 1, wherein the plurality of entity data includes variable-length data.

11. The database system according to claim 1, wherein

a plurality of the identifier tables is provided,

the database further includes a reference table having a set of reference identifiers that uniquely indicate the data identifiers in the plurality of identifier tables, and

the data processing unit performs the data processing using the reference table and the identifier tables.

12. The database system according to claim 11, wherein

each of the identifier tables includes at least one tuple that is defined in a row direction, an attribute field that is defined in a column direction and includes tuple identifiers, and an attribute field that is defined in the column direction and includes the data identifiers, and

the reference table includes at least one tuple that is defined in a row direction and at least one attribute field that is defined in a column direction and includes the reference identifiers.

13. The database system according to claim 11, wherein

the storage area allocated to the entity data group is divided into a plurality of partition areas, and

the plurality of partition areas is allocated as areas that store different types of entity data in the entity data group.

14. The database system according to claim 11, wherein

the database includes a plurality of sub-entity data having content related to the plurality of entity data,

the entity data and the sub-entity data having content related to the entity data are stored in continuous storage areas, and

when selecting entity data from the entity data group by searching the identifier table, the data processing unit reads sub-entity data having content related to the selected entity data from the database.

15. The database system according to claim 11, wherein

the database includes a plurality of sub-entity data having content related to the plurality of entity data,

position data indicating the position of the storage area of the sub-entity data having content related to the entity data is added to the respective entity data, and

when selecting entity data from the entity data group by searching the identifier table, the data processing unit reads sub-entity data designated by the position data added to the selected entity data from the database.

16. The database system according to claim 15, wherein

the position data indicating the position of the storage area of the sub-entity data is an address designating the absolute position of the storage area of the sub-entity data.

17. The database system according to claim 15, wherein

the position data indicating the position of the storage area of the sub-entity data is an offset designating the relative position of the storage area of the sub-entity data.

18. The database system according to claim 11, wherein

the database includes a plurality of sub-entity data having content related to the plurality of entity data,

the identifier table further includes sub-data identifiers that are in one-to-one correspondence with the data identifiers and uniquely indicate the sub-entity data, and

when selecting entity data from the entity data group by searching the identifier table, the data processing unit reads sub-entity data having content related to the selected entity data from the database using the sub-data identifiers.

19. The database system according to claim 11, wherein

the database includes at least one sub-entity data group having content related to the entity data group,

the storage unit includes a first storage area allocated to the entity data group and a second storage area allocated to the sub-entity data group, and

the data processing unit selects one of the first storage area and the second storage area on the basis of the received query.

20. The database system according to claim 1, wherein

the query is described with a query language, and

the data processing unit analyzes the query and performs, as the data processing, a transaction on the database on the basis of the analysis result.

21. A method of managing a database, comprising:

receiving a query for a database including an entity data group containing a plurality of entity data and at least one identifier table having only a plurality of fixed-length data; and

performing data processing on the database on the basis of the received query,

wherein the identifier table has, as the fixed-length data, a plurality of data identifiers that uniquely indicate the plurality of entity data.

22-48. -48. (canceled)

49. A non-transitory computer-readable storage medium storing a program for causing a computer to execute a database management process, the database management process comprising:

receiving a query for a database including an entity data group containing a plurality of entity data and at least one identifier table having only a plurality of fixed-length data; and

performing data processing on the database on the basis of the received query, wherein

the identifier table has, as the fixed-length data, a plurality of data identifiers that uniquely indicates the plurality of entity data.

50-63. -63. (canceled)